LIBRARY  OF  THE 

UNIVERSITY  OF  ILLINOIS 

AT  URBANA-CHAMPAIGN 


AGRICULTURE 


CIRCULATING 


CHECK  FOR  UNBOUND 
CIRCULATING  COPY 


Agricultural  Experiment  Station 

UNIVERSITY  OF  ILLINOIS 


BULLETIN  No.  275 


APPLE  BREEDING  AT  THE 
UNIVERSITY  OF  ILLINOIS 


BY  CHARLES  S.  CRANDALL 


URBANA,  ILLINOIS,  JUNE,  1926 


FOREWORD 

Apple  breeding  now  in  progress  at  the  Illinois  Agricultural 
Experiment  Station  was  instituted  in  1907.  In  that  year  projects 
were  outlined,  schedules  of  procedure  were  adopted,  and  the  collection 
of  breeding  material  was  begun.  The  projects  proposed  were  outlined 
under  five  divisions  as  follows: 

1.  Bud  selection:  an  attempt  to  determine  whether  or  not  per- 
manent improvement  in  varieties  of  apples  can  be  effected  thru  propa- 
gation from  selected  buds. 

2.  Growing  seedlings  from  exceptional  trees:  an  attempt  to  de- 
termine whether  or  not  improvement  in  varieties  of  apples  can  be 
effected  by  growing  seedlings  from  trees  that  have  attracted  attention 
by  reason  of  productiveness  and  exceptional  character  of  fruit. 

3.  Hybridizing  reciprocally  between  standard  varieties  of  apples 
and  such  other  species  and  varieties  of  the  genus  Malus,  both  foreign 
and  domestic,  as  can  be  brought  to  flowering. 

4.  Hybridizing  standard  orchard  varieties  with  a  view  to  secur- 
ing combinations  of  the  most  desirable  characters  of  both  parents. 

5.  Crossing  different  strains  of  the  same  variety  or  selected  indi- 
viduals of  the  same  strain. 

Divisions  1  and  2  were  considered  in  Bulletin  211,  "Apple-Bud 
Selection;  Apple  Seedlings  from  Selected  Trees,"  issued  in  1918.  The 
purpose  of  the  present  publication  is  to  consider  divisions  3,  4,  and  5, 
not  for  the  purpose  of  presenting  results,  for  results  are  only  just  be- 
ginning to  accrue,  but  to  bring  together,  in  form  for  convenient  refer- 
ence, the  data  accumulated  up  to  and  including  1924,  to  describe  and 
discuss  the  various  species  and  varieties  that  have  been  used  as  par- 
ents, to  give  in  some  detail  the  methods  used  in  performing  the  various 
operations,  and  to  record  the  present  status  of  more  than  20,000  seed- 
ling trees  that  have  been  grown  from  the  seeds  of  hybridized  fruits. 


TABLE  OF  CONTENTS 

PAGE 

INTRODUCTION . .  341 

PROCEDURE  FOLLOWED  IN  POLLINATING  WORK 342 

SPRING  WEATHER  AND  FLOWERING 342 

LENGTH  OF  BLOOMING  PERIOD 343 

LENGTH  OF  THE  PERIOD  OF  POLLINATIQN  WORK 344 

RECORDING  EMASCULATIONS  AND  POLLINATIONS 347 

METHODS  OF  EMASCULATING  APPLE  BUDS 347 

PROTECTING  EMASCULATED  BUDS 348 

METHOD  OF  LABELLING  CLUSTERS 348 

COLLECTING  AND  PRESERVING  POLLEN 349 

DESCRIPTION  OF  APPLE  POLLEN 351 

APPLICATION  OF  POLLEN  TO  STIGMAS 352 

SOME  GENERAL  CONSIDERATIONS  REGARDING  RESULTS  OF  POLLINATIONS...  353 

SOME  OF  THE  CAUSES  OF  FAILURES  OF  POLLINATIONS 356 

THE  PLANT  BREEDING  HOUSE 359 

COLLECTING  TREES  FOR  FORCING  PURPOSES 362 

COLLECTING  BREEDING  MATERIAL 364 

ORCHARD  VARIETIES 364 

SPECIES  AND  VARIETIES  OF  MALUS 369 

HYBRIDIZING :  DIVISION  INTO  CLASSES  AND  GROUPS 376 

GROUP  1 :  ORCHARD  VARIETIES  X  ORCHARD  VARIETIES 377 

Origin  of  Cultivated  Varieties 378 

Varieties  Used  as  Parents  for  Hybrids  of  Group  1 381 

Seed  Production  in  Hybrid  Fruits  in  Group  1 386 

Seeds  Planted  in  Group  1 387 

Seed  Losses 389 

Percentages  of  Germination  Vary  Widely 390 

Hybrid  Seedlings  Now  Living 39D 

Individual  Records  in  Group  1 392 

GROUP  2:  ORCHARD  VARIETIES  X  CRAB-LIKE  FORMS  OF  MALUS 399 

Hybridizing  Work  of  Dr.  Saunders  and  Others 399 

Varieties  Used  as  Pistillate  Parents  in  Matings  of  Group  2 402 

Forms  of  Malus  Used  as  Pollen  Parents  in  Matings  of  Group  2 ....  403 
Performance   of   Certain   Orchard  Varieties  When   Pollinated   by 

Crab-like  Forms 405 

Seed  Production  in  Hybrid  Fruits  of  Group  2 410 

Season  of  Maturity  of  Hybrid  Fruits 411 


Losses  of  Seeds  Between  Extraction  and  Planting 412 

Percentage  of  Germination  Higher  in  Group  2  Than  in  Group  1 . .  412 

Hybrid  Seedlings  Now  Living 414 

Individual  Records  in  Group  2 415 

GROUP  3:  CRAB-LIKE  FORMS  OF  MALTJS  X  ORCHARD  VARIETIES 419 

Forms  of  Malus  Used  as  Pistillate  Parents 419 

Varieties  Used  as  Pollen  Parents  in  Group  3 424 

Performance  of  Some  of  the  Pollen  Varieties. 425 

Seed  Production  and  Distribution  in  Group  3 427 

Period  of  Fruit  Maturity 430 

Loss  of  Seeds  Between  Extraction  and  Planting 430 

Percentage  of  Germination  Lower  in  Group  3  Than  in  Other 

Groups 431 

Hybrid  Seedlings  Now  Living 432 

Detailed  Performance  of  Some  Crab-like  Forms  on  Which  Pollen 

of  Orchard  Varieties  Was  Used 432 

GROUP  4:  CRAB-LIKE  FORMS  OF  MALUS  X  CRAB-LIKE  FORMS  OF  MALUS.  . .  437 

Seed  Production  and  Distribution  in  Group  4 441 

Losses  of  Seeds  Between  Extraction  and  Planting 442 

Percentages  of  Germination  Vary  Widely 442 

Hybrid  Seedlings  Now  Living 444 

THE  GENUS  MALUS 445 

DESCRIPTION  OF  MALUS  FORMS  USED  IN  BREEDING 447 

(For  alphabetical  index  to  forms  used  in  breeding,  see  page  599) 


APPLE  BREEDING  AT  THE 
UNIVERSITY  OF  ILLINOIS 

By  CHARLES  S.  CRANDALL,  Chief  in  Plant  Breeding  in  Horticulture 

INTRODUCTION 

At  the  beginning  or  very  early  in  the  development  of  any  con- 
templated plan  of  apple  breeding,  the  breeder  is  sure  to  be  confronted 
by  certain  discouraging  features.  There  is  first  the  interval  between 
generations;  the  certainty  that  a  long  period  of  patient  waiting  must 
precede  attainment  of  any  results  whatever  touching  the  method  of 
transmission  of  fruit  characters.  There  is  also  the  probability  that 
when  first  generation  hybrids  are  brought  to  fruiting,  at  the  end  of 
nearly  or  quite  a  full  decade,  it  will  appear  that  only  the  first  of 
several  equally  long  but  necessary  steps  has  been  taken  towards  a 
satisfactory  understanding  of  the  principles  involved  in  the  descent 
of  specific  characters. 

A  further  difficulty,  growing  out  of  the  recognized  confusion 
in  nomenclature  that  prevails  within  the  genus,  is  that  of  establishing, 
in  any  satisfactory  way,  the  systematic  positions  of  the  various  forms 
that  it  is  proposed  to  hybridize.  Still  another  source  of  discourage- 
ment is  that  encountered  in  attempting  to  describe  the  numerous 
forms  in  such  manner  that  the  differentials  will  serve  the  purpose  of 
definitely  distinguishing  one  form  from  another;  inconstancy  is  an 
attribute  of  many  of  the  characters  commonly  employed  to  differenti- 
ate species  and  varieties.  Most  of  the  characters  thus  far  studied 
exhibit  such  extremes  of  variation  as  to  bring  them  in  question  as 
elements  of  a  substantial  basis  upon  which  separation  of  forms  may 
safely  rest. 

It  is  the  misfortune  of  the  apple  breeder  that  the  material  with 
which  he  works  is  mongrel.  The  commonly  available  varieties  of  the 
orchard  have  been  perpetuated  by  asexual  propagation  for  long 
periods;  historical  data  regarding  time,  place,  and  manner  of  origin 
are  wanting,  and  nothing  whatever  is  known  regarding  remote  or 
even  immediate  ancestors.  This  same  condition  applies  to  all  intro- 
duced crab-like  forms;  grown  for  indefinite  periods  in  association  with 
other  forms,  passed  thru  an  unknown  number  of  seminal  generations, 
they  have  come  as  ornamentals,  most  of  them  bearing  evidences  of 
hybridization,  but  unaccompanied  by  historical  facts  and  their  origin 
wholly  a  matter  of  conjecture. 

Since  nothing  is  known  of  the  gametic  composition  of  the  apple 
forms  available  for  breeding,  and  nothing  of  the  potency,  constancy, 

341 


342  BULLETIN  No.  27f>  [June, 

or  heritable  qualities  of  characters  possessed  by  individuals,  there  is 
no  tangible  basis  from  which  the  results  of  any  particular  cross  can 
be  predicted.  The  attempt  to  combine,  in  the  progeny,  two  desirable 
qualities,  one  possessed  by  each  of  the  two  individuals  mated,  is  as 
likely  to  result  in  the  entire  elimination  of  one  or  both  of  the  qualities, 
so  far  as  their  presence  is  apparent  to  the  senses,  as  in  the  unimpaired 
retention  of  either  or  both,  in  sensible  form,  in  a  single  individual. 
The  qualities  in  question  appeared,  each  in  a  single  individual,  at 
some  remote  period;  they  have  been  maintained  by  vegetative  propa- 
gation and  there  is  no  way  of  judging  how  they  will  behave  when 
combined  in  company  with  numerous  other  characters  any  of  which 
may,  in  meeting  its  proper  mate,  assume  ascendancy  over  the  chosen 
characters. 

How,  then,  are  forms  for  mating  to  be  chosen?  The  writer  has 
no  answer  to  this  question  other  than  to  express  the  opinion  that  in 
the  absence  of  knowledge  of  the  qualities  of  particular  characters  no 
intelligent  selection  of  parents  can  be  made.  A  first  essential  is  to 
learn  by  actual  matings  how  the  various  characters  of  parents  appear, 
or  fail  to  appear,  in  the  progeny.  Are  they  transmitted  intact,  do 
they  appear  in  modified  forms,  or  are  they  entirely  suppressed?  Facts 
that  will  assist  in  answering  these  questions  are  confidently  expected 
from  the  numerous  hybrid  progeny  now  growing  in  the  orchards. 
These  seedlings  represent  numerous  combinations,  many  of  which  were 
made  with  specific  objects  in  view,  some  from  motives  of  convenience, 
and  some  as  purely  random  matings.  Naturally  great  interest  centers 
in  these  hybrid  seedlings,  because  if  they  do  not  throw  such  light  upon 
the  nature  of  the  characters  of  the  various  forms  as  will  serve  to  guide 
future  matings,  then  will  the  labor  have  been  in  vain. 

PROCEDURE  FOLLOWED  IN  POLLINATING  WORK 
SPRING  WEATHER  AND  FLOWERING 

Pollination  of  flowers  of  apple  varieties  in  the  orchard  is  attended 
with  many  uncertainties  because  of  unfavorable  weather  conditions  at 
blooming  time.  These  conditions  vary  greatly  in  different  seasons  and 
may  affect  the  work  of  pollination  by  departures  from  normal  in 
either  direction.  In  some  seasons  the  flowering  season  is  extended 
over  about  two  weeks,  or  even  a  little  more;  this  means  rain,  low 
temperatures,  high  winds,  and  conditions  generally  unfavorable  to 
flower  development  and  to  success  in  pollination. 

Sometimes  there  are  frosts,  but  cold  rains  and  high  winds,  even 
in  the  absence  of  frost,  may  so  impair  the  vitality  of  floral  organs 
that  the  most  careful  applications  of  pollen  to  stigmas  fail  to  result  in 
fruits.  When  such  conditions  prevail,  flowers  do  not  open  normally, 
filaments  do  not  elongate,  styles  remain  short  with  stigmas  clustered 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  343 

in  the  center  of  the  flower;  and  the  manual  operations  of  emasculation 
and  pollination  are  performed  with  difficulty  and  discomfort,  and  dis- 
couragement is  the  net  result. 

On  the  other  hand,  a  hot  wave  with  accompanying  bright  sun 
and  balmy  breeze  will  push  buds  with  such  rapidity  that  all  flowers 
open  nearly  at  the  same  time ;  thus  the  flowering  period  is  so  shortened 
that,  even  with  all  preliminaries  arranged  to  expedite  procedure,  pol- 
linations fall  far  short  of  what  it  was  hoped  and  expected  would  be 
accomplished.  If  the  hot  wave  comes  sufficiently  late  and  is  not  fol- 
lowed by  killing  frosts,  crops  are  produced,  pollinations  are  reasonably 
successful,  and  the  breeder  regrets  only  the  limited  amount  of  work 
performed.  But  if  the  heat  that  unduly  stimulates  comes  early,  the 
probability  of  disaster  from  bad  storms  amounts  to  almost  a  certainty. 

The  date  of  full  bloom  for  Oldenburg  in  this  locality,  as  averaged 
from  the  records  of  twenty  years,  is  May  2.  In  1910  the  first  flower 
opened  April  3  and  full  bloom  was  recorded  for  April  8.  A  storm 
April  23-25,  during  which  there  was  rain,  snow,  high  wind,  and  freez- 
ing temperatures,  completely  ruined  the  prospective  crop.  For  the 
twenty  years  for  which  the  average  date  of  full  bloom  was  computed, 
two  years — 1902  and  1912 — had  the  average  date,  full  bloom  fell  on 
later  dates  in  eight  years  and  on  earlier  dates  in  ten  years.  The  years 
of  full  crops  were  included  in  the  eight  years  of  late  bloom,  but  even 
here  some  injury  from  frost  was  inflicted  in  two  of  the  seasons.  The 
lean  years  were  the  years  of  early  bloom,  for  in  each  of  the  ten  years 
there  was  more  or  less  serious  injury  from  bad  weather.  Only  in  the 
years  1910  and  1919  was  the  destruction  complete. 

LENGTH  OF  BLOOMING  PERIOD 

The  length  of  blooming  period  is  extremely  variable,  with  the 
extremes  far  apart.  The  full  period  was  ten  days  in  1901  and  1915, 
and  twenty-two  days  in  1907.  The  average  of  all  years  is  sixteen 
days.  Blooming  periods  for  individual  varieties  vary  widely  and 
with  great  irregularity.  A  variety  having  a  four-day  period  in  one 
season  may  have  the  period  lengthened  in  another  year  to  as  much 
as  sixteen  days.  Two  varieties,  one  having  a  blooming  period  three 
times  as  long  as  the  other  in  any  one  year,  may  exactly  reverse  this 
relation  in  a  following  year.  No  variety  is  constant  in  length  of 
blooming  period,  but  some  varieties  vary  more  widely  than  others. 
Causes  for  the  irregularities  observed  are  difficult  to  determine,  in 
any  definite  way,  because  the  factors  involved  are  too  numerous  and 
varied.  Of  course  weather  conditions  are  important,  but  the  condition 
of  the  individual  is  equally  important  and  is  dependent  upon  condi- 
tions to  which  it  has  been  subjected  thru  preceding  months  or  years; 
qualities  are  developed  that  render  it  more  susceptible  to  stimulation 
or  less  resistant  to  adverse  conditions  in  one  season  than  in  another. 


344 


BULLETIN  No.  275 


[June, 


This  phase  of  the  subject  has  been  treated  in  some  detail  in 
Bulletin  251,  "Blooming  Periods  of  Apples,"  issued  in  May,  1924. 

LENGTH  OF  THE  PERIOD  OF  POLLINATION  WORK 

The  number  of  days  over  which  the  field  work  of  emasculation 
and  pollination  extends  varies  in  different  seasons  according  to  the 
weather,  and  has  ranged,  for  the  last  fifteen  years  (1909  to  1923) 
from  three  to  twenty-two  days  for  emasculation,  and  from  three  to 
eighteen  days  for  pollinations,  or  the  full  period  from  the  first  emas- 
culation to  the  last  pollination  has  varied  from  five  days  in  1920  to 

TABLE  1. — LENGTH  OF  POLLINATION  PERIOD  FOR  EACH  OF  THE  YEARS 

1909  TO  1923 


Year 

Emasculations 

Pollinations 

Full  period 
of  work, 
days 

Begun 

•  Ended 

Days 

Begun 

Ended 

Days 

1909. 

May  1 

May  7 

7 

May  4 

May  10 

7 

10 

1910. 

Apr.  4 

Apr.  14 

11 

Apr.  7 

Apr.  20 

14 

17 

1911. 

May  1 

May  10 

10 

May  4 

May  12 

9 

12 

1912. 

Mav  1 

May  6 

6 

Mav  6 

May  8 

3 

8 

1913. 

Apr.  29 

May  6 

8 

May  3 

May  7 

5 

9 

1914 

Apr.  29 

May  4 

6 

May  1 

May  5 

5 

7 

1915. 

Apr.  23 

Apr.  27 

5 

Apr.  27 

Apr.  29 

3 

7 

1916. 

Apr.  28 

May  9 

12 

May  2 

May  11 

10 

14 

1917. 

Apr.  25 

May  16 

22 

May  1 

May  18 

18 

24 

1918. 

Apr.  27 

May  8 

12 

Apr.  30 

May  9 

10 

13 

1919. 

Apr.  22 

Apr.  22 

1920. 

Mav  11 

Mav  13 

3 

May  13 

May  15 

3 

'5 

1921. 

Apr.  21 

Apr.  26 

6 

Apr.  23 

Apr.  28 

6 

8 

1922. 

Apr.  21 

May  2 

12 

Apr.  24 

May  3 

10 

13 

1923. 

Mav  2 

May  12 

11 

May  5 

May  14 

10 

13 

twenty-four  days  in  1917.  Records  of  the  actual  days  of  pollination 
work  for  the  fifteen  years  appear  in  Table  1. 

In  1910  the  storm  that  brought  temperatures  low  enough  to  kill 
all  fruits  did  not  begin  until  three  days  after  the  last  pollinations 
were  made.  In  1919  there  was  no  protracted  storm,  as  in  1910,  but 
temperatures  went  low  enough,  on  the  morning  of  April  23  and  again 
on  April  24,  to  kill  blossoms  and  stop  emasculating,  which  had  been 
begun  on  April  22. 

The  longest  full  period  was  that  of  1917,  April  25  to  May  18, 
twenty-four  days;  ordinarily  a  flowering  period  thus  extended  would 
mean  storms  and  dangerously  low  temperatures,  but,  in  this  instance, 
there  were  no  severe  storms  and  blossoms  were  not  subjected  to  injury 
from  frost.  There  prevailed  a  period  of  reasonably  pleasant  weather 
with  temperatures  low  enough  to  retard  flower  development.  Hot 
waves,  such  as  occurred  in  1912  and  1915,  which  brought  flowers 
forward  so  rapidly  that  the  days  of  pollinations  were  reduced  to  three, 
were  absent  in  1917.  Conditions  in  this  year  approximated  the 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  345 

breeder's  ideal;  there  were  no  storms  to  cause  injury,  nor  heat  waves 
to  unduly  crowd  the  work. 

Practice  at  this  Station  has  been  to  separate  the  operations  of 
emasculation  and  pollination.  A  schedule  of  the  desired  crosses  is 
prepared  in  advance  and  emasculation  begins  as  soon  as  buds  are 
sufficiently  developed.  The  entire  force  engages  in  emasculation  for 
one,  two,  or  three  days,  depending  upon  the  amount  of  work  and  the 
rate  at  which  buds  are  advancing  toward  anthesis;  then  there  is  a 
division:  several  workers  continue  emasculating  while  others  begin 
pollination,  taking  first  the  earliest  emasculations.  Toward  the  end 
of  the  campaign  all  workers  assist  in  completing  the  pollination  of 
flowers  that  have  been  emasculated;  the  aim  is  to  come  out  even  and 
as  near  the  limit  of  time  for  possible  pollinations  as  may  be.  Some- 
times, when  the  end  is  in  sight  and  it  is  discovered  that  certain  late 
flowering  varieties  still  have  workable  buds,  additional  emasculations 
are  made,  but  with  these,  pollination  is  performed  at  the  time  of 
emasculation. 

Some  breeders  advocate  pollination  at  the  time  of  emasculation 
as  the  most  satisfactory  practice,  and  there  are  a  number  of  points 
in  favor  of  such  practice,  particularly  in  that  it  completes  the  work  at 
•one  operation;  but  having  given  both  methods  a  somewhat  extended 
trial,  the  opinion  is  retained  that  for  the  climatic  and  labor  conditions 
under  which  the  work  is  done  at  this  Station  the  method  of  deferred 
pollination  is  decidedly  the  more  satisfactory.  One  of  the  points  in 
favor  of  this  procedure  lies  in  the  fact  that  there  is  opportunity  to 
check  the  character  of  the  work  done  in  emasculating,  and  where 
student  or  other  unskilled  labor  is  sometimes  employed  this  is  im- 
portant. Upon  the  removal  of  the  bags,  at  the  time  of  pollinating, 
flowers  are  not  infrequently  found  that  were  incompletely  emascu- 
lated or  that  had  been  injured  by  some  slip  of  the  tool  used  in  emas- 
culating; such  flowers  may  then  be  discarded,  because  if  allowed  to 
remain  they  serve  no  purpose  except  to  increase  the  error  in  compu- 
tation of  success  percentages. 

There  is,  of  course,  a  very  definite  limit  to  the  length  of  time 
application  of  pollen  can  be  deferred;  this  limit  depends  chiefly  upon 
temperature  and  upon  the  degree  of  advancement  of  the  buds  at  time 
of  emasculation.  If  temperatures  abnormally  high  for  the  season  are 
prevailing,  the  interval  must  be  shortened  to  one  or,  at  most,  two 
days;  if  temperatures  are  so  low  that  development  of  floral  organs  is 
slow,  the  interval  may  extend  to  four  or  five  days.  It  is  essential  that 
pollen  be  applied  before  there  is  any  evidence  of  browning  of  the 
styles,  and,  on  the  other  hand,  it  should  not  be  applied  until  exuda- 
tion of  the  stigmatic  secretion  indicates  a  receptive  condition.  It  is 
only  necessary  to  observe  carefully  the  rate  of  development  and  govern 


346  BULLETIN  No.  275 

APPLES:     Pollination  Sec«rd  Spring  of  IS /& 


[June, 


female  Parent 
Location 


Male  Parant  8  33  9ft. 


Bow  / 


.  by 


vf/  x/ 


Date  pollen  taken 


Hourly*-.  Poll,  by  /^  /f./         Brte 
Hour  <7  «  T>?  Age  of  pollen  (in  houri) 


Sow  /  Trae  3/ 

*%T    VmxSj.*.. 


Serial 

Nuicber 


No.  f  Is.  in 

cluster 


tfo.fls. 


7/26 


Ko.  fruit* 
picked 


Date  picked  and  d«scribed 


10601 


10602 


10603 


2- 


10604 


10605 


V 


10606 


10607 


10608 


10609 


10610 


10611 


10612 


2- 


10613 


V 


10614 


till. 


10615 


10616 


10617 


J" 


10610 


10619 


jT 


10620 


10621 


L0622 


- 


10623 


10624 


10625 


FIG.  1. — POLLINATION  SHEET;  REPRODUCTION  OF  AN  ACTUAL  RECORD 
Records   were   kept    on  loose   sheets   of   heavy   paper   measuring  S1/^ 
by  11  inches.  When  the  record  was  filled,  the  sheets  were  inserted  in  ring- 
binders  for  permanent  reference. 

action  by  these  observations  in  order  to  make  the  applications  at  the 
time  when  the  condition  of  the  stigmas  is  at  its  best. 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  347 

RECORDING  EMASCULATIONS  AND  POLLINATIONS 

Reference  has  been  made  to  pollinations,  and  some  explanation 
should  be  given  of  the  method  adopted  for  recording  and  labelling. 
Records  are  kept  on  what  are  known  as  "pollination  sheets"  (Fig.  1) ; 
these  are  letter-size  sheets  of  heavy  paper,  which,  when  filled,  are 
bound  for  easy  reference  in  "ring-binders." 

At  the  time  of  emasculation,  the  name  and  location  of  the  tree  are 
entered,  and  the  two  columns,  number  of  buds  to  the  cluster  and  num- 
ber emasculated,  are  filled.  The  rule  with  orchard  varieties  is  to 
emasculate  two  buds  in  each  cluster  used;  the  others  are  removed. 
It  is  preferred  that  only  one  of  the  two  emasculated  buds  in  each 
cluster  develop  as  fruit  and  certainly  no  more  than  two  fruits  are 
desirable  for  any  one  cluster.  With  crab-like  forms  that  commonly 
bear  the  fruits  in  clusters  of  from  three  to  six,  all  buds,  except  ab- 
normally small  ones,  are  emasculated,  and  frequently  several  clusters 
are  bagged  under  one  number. 

At  the  time  of  pollination,  the  name  and  location  of  the  pollen 
parent,  day  and  hour  of  pollination,  and  age  of  pollen  are  entered, 
and  the  column  "Number  of  flowers  pollinated"  is  filled.  In  use,  the 
sheet  is  held  to  a  backing  of  binder's-board  by  rubber  bands  and  may 
lie  on  the  broad  top  of  the  step-ladder,  or  may  be  hung  from  a  twig, 
as  seems  most  convenient. 

METHODS  OF  EMASCULATING  APPLE  BUDS 

The  aim  in  emasculating  is  to  remove  all  of  the  anthers  before 
the  commencement  of  dehiscence  and  without  injury  to  the  pistil;  this 
can  be  accomplished  most  readily  when  buds  are  on  the  point  of 
opening,  because  then  the  filaments  have  become  elongated  and  the 
anthers  are  not  so  closely  associated  with  the  pistil  as  in  less  developed 
buds.  However,  when  a  large  number  of  emasculations  is  contemplated, 
it  is  manifestly  impossible  to  have  all  buds  in  this  ideal  condition. 
Usually  there  are  differences  in  the  degree  of  development  of  the  buds 
of  a  cluster  and  those  nearest  the  desired  development  may  be  selected ; 
at  the  beginning  of  the  season  the  larger  are  chosen,  near  the  end  the 
smaller,  because  the  larger  are  partly  or  fully  open  and  must  be 
discarded. 

There  are  two  methods  of  emasculating  apple  buds,  each  of  which 
has  its  advocates.  The  petals  may  be  forced  aside  or  cut  off  and  the 
anthers  picked  out  with  tweezers,  or  cut  out  with  scalpel  or  scissors; 
by  this  method  there  is  no  mutilation  of  remaining  parts  except  the 
petals.  By  the  other  method  the  calyx  cup  is  cut  thru,  just  below 
insertion  of  the  stamens,  thus  removing  all  floral  organs  except  the 
pistil.  With  the  peach  this  last  method  is  much  the  easiest,  most 
expeditious,  and  is  practiced  without  danger  to  the  pistil,  because  the 


348  BULLETIN  No.  275  [June, 

ovary  is  free  and  the  calyx  cup  is  relatively  broad.  In  the  apple  bud 
the  calyx  is  adnate  to  the  ovary,  the  calyx  cup  is  contracted  and 
insertion  of  stamens  brought  into  such  close  proximity  to  the  pistil 
that  extreme  care  is  necessary  in  guiding  the  cutting  tool  to  effect  the 
purpose  without  injury  to  the  central  organ.  A  minor  objection  to  this 
method  is  that  such  fruits  as  develop  are  more  or  less  deformed  by 
removal  of  the  calyx.  Both  methods  have  been  used,  but  emascula- 
tion without  unnecessary  mutilation  is  regarded  as  the  better. 

PROTECTING  EMASCULATED  BUDS 

Nothing  has  been  found  that  serves  the  purpose  of  protecting 
emasculated  buds  so  well  as  size  No.  1  paper  bags.  Care  is  necessary 
in  choosing  the  brand',  for  all  bags  are  not  equal  in  the  essentials — 
lightness,  toughness,  and  resistance  to  rain.  Protracted  rain  accom- 
panied or  followed  by  high  wind  will  sometimes  destroy  the  best  bags 
made  by  constant  whipping  about,  but  little  loss  has  been  experienced 
from  this  cause.  In  adjusting  the  bags,  care  should  be  taken  to  expand 
the  satchel  bottoms  to  the  fullest  extent  so  that  they  may  stand  away 
from  the  buds.  Bags  are  tied  on  with  cotton  cord  cut  to  proper  lengths 
and  carried  in  such  manner  as  to  be  ready  at  hand  as  wanted;  the 
length  should  admit  tying  in  a  single  bowknot  so  that  untying  is  easy 
when  the  time  comes  to  remove  for  pollinating. 

In  choosing  clusters  the  flowers  of  which  are  to  be  emasculated,  the 
matter  of  position  is  worthy  of  attention.  The  ease  with  which  the 
subsequent  operations  of  tying  the  sack  and  of  pollinating  are  per- 
formed will  depend  upon  the  choice  of  clusters,  and  usually  bloom  is 
so  abundant  that  only  such  clusters  as  are  conveniently  situated  need 
be  taken.  Terminal  clusters  of  very  short  spurs  from  large  branches 
are  not  considered  desirable  because  they  are  difficult  to  cover,  and 
terminal  clusters  of  long,  willowy  shoots  are  liable  to  injury  from 
whipping  about  by  wind. 

METHOD  OF  LABELLING  CLUSTERS 

As  soon  as  the  two  flowers  of  a  chosen  cluster  are  emasculated, 
the  record  of  that  cluster  is  entered  on  the  sheet  opposite  one  of  the 
serial  numbers;  then  a  label  bearing  a  corresponding  number  is 
attached  close  enough  to  the  cluster  to  be  identified  as  belonging  to  it. 
This  label  establishes  a  permanent  relation  between  the  cluster  and 
the  written  record  of  the  cluster;  it  must  be  securely  attached  and 
must  remain  readily  legible  thru  five  or  six  months'  exposure  to  sun, 
wrind,  and  rain. 

The  labels  are  prepared  in  advance.  They  are  strung  on  wire 
hooks  in  lots  of  twenty-five,  the  labels  on  each  hook  corresponding 
to  the  serial  numbers  of  a  particular  sheet,  while  the  numbers  they 
bear  are  in  the  same  sequence  as  the  serial  numbers  on  the  sheet.  The 


1986] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


349 


FIG.  2. — LABELS  USED  ON  TREES  TO 
IDENTIFY  CLUSTERS 

When  these  labels  were  photographed  they 
had  hung  on  trees  in  the  orchard  for  292  days — 
from  April  14,  1910,  to  January  31,  1911. 


label  used  with  entire  satisfaction  for  several  years  is  the  standard 
string  tag  No.  542  made  by  the  Dennison  Company.  This  gives  a 
writing  surface  %  inch  square,  sufficient  for  the  number,  which  is  all 
that  need  be  placed  on  the  label.  The  number  is  put  on  with  a  brush, 
using  a  paint  consisting  of  shellac,  cut  in  alcohol,  to  which  is  added 
sufficient  lamp-black  to  give  color;  this  paint  dries  immediately  and 
the  numbers  remain  legible  far  beyond  the  necessary  limit.  Fig.  2 
shows  three  of  these  labels  as  they  appeared  after  hanging  on  the 

trees  for  292  days.  The 
labels  are  quickly  at- 
tached by  simply  loop- 
ing the  cord  about  the 
twig. 

COLLECTING  AND  PRE- 
SERVING POLLEN 

Providing  a  sufficient 
supply  of  pollen  for  use 
as  wanted  is  one  of  the 
important  requirements 
of  the  pollinating  season. 
It  is  most  readily  ob- 
tained from  flowers  just 

opening  or  from  buds  nearly  ready  to  open.  The  usual  procedure  is  to 
select  small  branches  on  which  a  considerable  portion  of  the  buds  are 
nearly  ready  to  open,  take  them  to  the  laboratory,  and  there  remove 
the  anthers.  If  temperatures  have  been  low  and  the  rate  of  bud  devel- 
opment slow,  the  branches  may  be  placed  in  water  in  the  greenhouse 
for  two  or  three  days  to  allow  further  development  of  anthers,  but  if 
high  temperatures  have  prevailed  and  all  conditions  have  been  favor- 
able to  the  rapid  maturity  of  buds,  it  is  not  unusual  to  extract  the 
anthers  immediately  after  collecting  the  branches.  It  is  essential  that 
the  anthers  be  mature  and  as  near  dehiscence  as  possible. 

Under  the  conditions  that  prevail  in  some  seasons,  orchard  trees 
burst  into  full  bloom  very  suddenly;  on  one  day  there  may  be  here 
and  there  an  open  flower,  while  on  the  following  day  practically  all 
flowers  are  open.  If  an  early  morning  examination  promises  opening 
of  the  mass  of  flowers  on  that  day,  branches  of  flowers  should  then  be 
gathered  from  which  to  extract  pollen.  By  discarding  such  flowers  as 
may  be  fully  open  and  such  retarded  buds  as  may  be  found,  reason- 
able uniformity  in  the  development  of  the  anthers  removed  may  be 
secured. 

Anthers  may  be  removed  either  with  tweezers  or  with  the  fingers. 
This  is  a  matter  of  personal  preference  on  the  part  of  those  doing  the 
work,  but  after  thoro  trial  of  both  methods  it  is  believed  that  anthers 


350  BULLETIN  No.  275  [June, 

can  be  more  rapidly  extracted  with  the  fingers  than  with  any  tool  yet 
devised.  The  anthers  as  extracted  fall  into  a  Petri  dish  10  cm.  in 
diameter,  or,  for  small  quantities  from  trees  supplying  only  a  few 
clusters  of  buds,  into  dishes  of  half  that  diameter.  When  anthers 
have  been  collected  in  considerable  quantity,  the  dishes  are  removed 
to  some  dry  place,  protected  from  currents  of  air,  and  allowed  to 
remain  until  the  anthers  have  opened;  this  requires  from  twenty-four 
to  forty-eight  hours  depending  upon  the  temperature  and,  largely, 
upon  the  humidity  of  the  air. 

Each  dish  is  labelled,  in  advance  of  use,  with  a  gummed  label 
placed  within  the  dish  on  the  bottom;  on  this  label  is  recorded  the 
name  or  number  of  the  variety,  the  location  of  the  tree,  and  the  day 
and  hour  of  collection.  Altho  the  label  might  be  read  more  easily  if 
placed  on  the  cover,  the  arrangement  invites  error  thru  possible  ex- 
change of  covers  when  a  number  of  similar  dishes  are  in  use.  When 
a  large  quantity  of  pollen  of  one  variety  is  desired  it  is  better  to  use 
two  or  three  dishes  than  to  place  the  entire  amount  in  one>  both 
because  the  small  content  of  the  dish  dries  out  more  quickly  and  the 
anthers  dehisce  better,  and  because  the  additional  dishes  insure  against 
loss  of  all  the  pollen  thru  accidental  over-turning  of  the  one  dish.  After 
the  anthers  have  dehisced,  covers  are  placed  on  the  dishes. 

Not  only  are  there  marked  differences  between  species  and  vari- 
eties of  Malus  in  abundance  of  pollen  produced,  but  there  are  wide 
differences  in  quality  and  also  in  behavior  of  the  pollen  after  de- 
hiscence  of  anthers.  In  some  varieties,  the  pollen,  even  when  pro- 
duced in  abundant  quantity,  persistently  adheres  to  the  anthers;  in 
others,  it  falls  readily.  In  some  the  grains  fall  in  masses  which  per- 
sist until  broken  up  mechanically,  in  others  the  grains  do  not.  adhere 
to  each  other  but  fall  singly,  giving  to  the  mass  a  powdery  appear- 
ance. Winesap  pollen  is  commonly  deficient  in  quantity,  often  with 
a  high  percentage  of  imperfect  grains,  and  usually  it  adheres  per- 
sistently to  the  anthers  after  dehiscence.  With  Jonathan,  Oldenburg, 
and  Yellow  Transparent,  the  pollen  is  abundant,  separates  readily 
from  the  anthers,  falls  as  a  fine  powder,  and  usually  contains  but  few 
imperfect  grains.  Malus  arnoldiana  and  Malus  sylvestris  fastigiata 
bifera  produce  abundant  pollen  which  falls  readily  from  the  anthers; 
with  Malus  ringo  the  pollen  is  equally  abundant  but  adheres  very 
persistently  to  the  anthers.  Malus  mains  var.  (19667)  produces  only 
a  small  quantity,  which  remains  adherent  to  the  anthers.  Stayman 
Winesap  has  very  plump  anthers,  and  pollen  is  abundant  and  strongly 
adherent;  when  this  pollen  falls  or  is  forcibly  brushed  from  the  anthers 
it  remains  indefinitely  in  small  masses  which  retain  the  orange  color 
of  fresh  pollen. 

Adherence  of  pollen  grains  to  each  other  or  to  the  anther  sack  is 
not  an  index  of  viability.  In  ability  to  fertilize,  the  most  persistently 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  351 

adherent  pollen  appears  equal  to  that  which  falls  as  powder,  but  the 
latter  type  is  more  easily  distributed  on  stigmas  and  is  preferred  for 
use  in  pollination. 

Pollen  collected  as  described  above  is  kept  in  the  Petri  dishes  and 
used  direct  from  these  dishes  as  long  as  there  are  flowers  to  be  pol- 
linated. The  only  precautions  taken  are  to  protect  the  pollen  from 
exposure  to  the  air,  and  to  store  the  dishes  in  a  dry  place  at  night. 

DESCRIPTION  OF  APPLE  POLLEN 

Normal  grains  of  apple  pollen,  in  the  dry  state  as  taken  from 
anthers,  are  elliptical,  or  oval,  in  form,  the  long  axis  usually  about 
one  and  three-fourths  times  the  length  of  the  transverse  axis;  the  sur- 
face is  smooth,  usually  with  a  single  longitudinal  fold  extending  from 
half  the  length  to  full  length  of  the  grain  in  some  cases.  Each  normal 
grain  has  three  pores,  or  thin  places,  in  the  outer  coat  (extine) ; 
these  are  situated  at  equal  intervals  at  the  circumference  midway  of 
the  long  axis. 

Because  of  the  densely  granular  content  of  the  grain,  these  thin 
places  are  not  readily  seen  in  the  dry  grain,  but  by  careful  adjustment 
in  relation  to  light  the  pores  can  be  brought  into  view  one  at  a  time, 
wken  they  appear  as  small  translucent  spots  sometimes  protruding 
slightly  beyond  the  surface.  On  application  of  water,  the  grains  im- 
mediately swell  and  become  almost  spherical;  even  with  pollen  that 
has  been  stored  for  months,  enlargement  takes  place  promptly  altho 
full  size  is  not  so  quickly  attained  as  in  the  case  of  fresh  pollen. 

In  swelling,  the  short  axis  elongates  until  it  approximates  the 
long  axis  in  length.  The  long  axis  usually  remains  much  as  in  the  dry 
grain,  but  may  vary  in  some  degree,  at  times  elongating  slightly  and 
again  becoming  slightly  shorter.  When  grains  are  wet,  the  pores  or  thin 
places  in  the  outer  coat  become  very  distinct  and  often  appear  as 
knob-like  protrusions;  they  give  to  the  grain  a  triangular  appearance 
when  viewed  from  the  end;  the  grains,  however,  are  almost  perfectly 
spherical,  as  is  readily  demonstrated  by  rolling  them  under  a  cover 
glass.  Treated  with  concentrated  sulfuric  acid,  the  thin  places  in  the 
outer  coat  as  well  as  the  inner  coat  and  the  granular  contents  are  dis- 
integrated ;  the  outer  coat  curves  outward  at  the  margins  of  the  open- 
ings and  the  walls  appear  divided  into  triangular  segments. 

In  germination  the  inner  coat  protrudes  from  these  pores  in  start- 
ing the  growth  of  the  pollen  tube.  The  three  pores  suggest  the  pos- 
sibility of  three  pollen  tubes,  but  usually  there  is  only  one.  In  only 
one  case  has  indication  of  a  second  tube  been  seen,  and  then  while  one 
tube  elongated  normally  the  other  remained  short,  attaining  a  length 
but  little  exceeding  the  diameter  of  the  grain.  In  all  lots  of  pollen 
examined  dry,  as  taken  from  the  anthers,  there  appeared  mingled  with 
the  normal  plump  grains,  a  varying  number  of  grains  that  were  spheri- 


352  BULLETIN  No.  275  [June, 

cal  and  of  small  size,  others  of  irregular  and  some  of  rectangular  form ; 
these  are  imperfectly  formed  grains  which  are  incapable  of  function- 
ing and  never  emit  tubes.  When  brought  into  contact  with  water  or 
when  placed  in  saccharine  solutions,  some  of  these  imperfect  grains 
promptly  burst  and  discharge  their  contents;  others  neither  burst  nor 
in  any  way  change  form,  but  remain  intact  indefinitely.  The  relative 
abundance  of  these  defective  grains  serves,  in  a  general  way,  as  an 
index  to  the  probable  value  of  the  pollen  for  use  in  crossing. 

Pollen  grains  from  different  species  and  varieties  of  Mains  exhibit 
some  slight  differences  in  size,  but  there  are  as  great,  or  in  some 
instances  greater,  differences  between  grains  from  different  individuals 
of  the  same  group  as  there  are  between  different  groups.  Size,  as  well 
as  the  relative  proportion  of  inferior  grains,  appears  to  depend  almost 
wholly  upon  the  health  and  vigor  of  the  individual  plant.  Measure- 
ments have  been  made  of  the  pollen  of  twenty  species  and  varieties  of 
Malus  and  of  five  orchard  varieties;  the  measurements  recorded  are 
the  averages  of  the  measurements  of  ten  grains,  dry  and  again  after 
application  of  water.  The  largest  grains  are  those  of  Malus  coronaria, 
which  measure  32  x  46  microns  when  dry,  and  48  x  53  microns  when 
wet.  The  smallest  grains  are  those  of  Malus  baccata,  measuring 
19  x  35  microns  dry,  and  34  x  35  microns  when  wet.  For  the  twenty 
species  and  varieties  of  Malus  the  average  is  23  x  40  microns  dry,  and 
36  x  40  microns  wet.  The  averages  for  the  five  orchard  varieties  are 
25  x  43  microns  dry,  and  38  x  42  microns  wet. 

APPLICATION  OF  POLLEN  TO  STIGMAS 

Buds  having  been  emasculated  and  stigmas  developed  to  a  fully 
receptive  stage,  the  next  procedure  is  to  apply  pollen.  This  may  be 
done  in  various  ways:  some  breeders  use  a  camel's  hair  brush,  others 
recommend  use  of  the  fingers;  the  handle  of  a  pair  of  tweezers  may 
be  used,  or  any  other  piece  of  polished  metal  of  proper  form,  or 
anthers  on  the  point  of  dehiscence  may  be  brushed  over  the  stigmas. 
There  is  no  more  effective  method  than  that  last  mentioned,  but  it  is 
impracticable  for  any  but  small  undertakings,  because,  if  the  pollen 
is  properly  guarded  against  contamination  the  work  cannot  be  done 
with  the  rapidity  desired  in  large  operations. 

Various  methods  have  been  used  in  work  at  this  Station,  but 
the  one  most  in  favor,  because  both  effective  and  expeditious,  is  that 
of  providing  the  pollen,  in  ample  quantity  where  possible,  in  Petri 
dishes  5  cm.  in  diameter,  and  thrusting  the  stigmas  directly  into  the 
pollen  mass  wherever  they  can  be  brought  into  such  position  as  to 
admit  this  procedure.  If  flowers  stand  erect  on  spurs  too  rigid  to  be 
deflected,  the  smooth  handle  of  tweezers  is  used  to  transfer  the  pollen 
from  the  dish  to  the  stigmas;  pollen  adheres  readily  to  this  tool  and 
is  easily  scraped  off  by  the  stigmas.  When  finished  with  one  kind  of 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


353 


pollen,  the  tweezers  are  quickly  sterilized  by  immersion  in  a  vial  of 
alcohol  and  at  once  are  ready  to  use  with  another  kind  of  pollen 

without   danger  of   contamination. 

The  chief  points  in  pollinating  are  to 
cover  the  stigmas  thoroly  with  pollen,  to 
use  only  well-developed  pollen  that  has 
been  thoroly  dried,  to  minimize  as  far  as 
possible  the  danger  of  admitting  unde- 
sired  pollen,  to  exercise  care  not  to  bend 
or  break  styles,  pedicels,  or  spurs,  and  to 
see  that  the  bags  when  readjusted  are  se- 
curely tied. 

Pollination  completed,  the  bags  remain 
undisturbed  until  it  is  convenient  to  make 
an  examination  and  ascertain  the  appar- 
ent success.  Usually  this  examination  is 
deferred  for  four  or  five  weeks,  or  until  it 
is  thought  probable  that  fruits  that  started 
without  having  been  fertilized  may  have 
fallen,  or  have  assumed  the  yellow  color 
indicating  an  early  fall.  The  only  objec- 
tion to  delayed  examination  that  has  thus 
far  appeared  'is  that  green  aphis  may  es- 
tablish colonies  within  the  sacks  and  de- 
stroy or  injure  the  young  fruits;  presence 
of  these  insects  can  be  determined  only  by 
removal  of  the  sack.  Since  cases  of  such 
invasion  have  not  been  common  and  the 
labor  of  examination  is  considerable,  the 
deferred  examination  will  be  continued, 
for  a  better  index  of  the  probable  number 
of  fruits  that  will  mature  is  obtained  then 
than  would  be  possible  earlier.  At  the 
time  of  this  examination  the  paper  bags 
are  removed,  record  is  made  of  failure  or 
apparent  success,  and  in  all  cases  where 
fruits  are  developing  a  cheesecloth  bag  replaces  the  paper  bag  to  re- 
main until  the  fruit  is  picked.  These  cloth  bags  serve  as  a  protection 
to  the  fruit  and  are  not  in  danger  of  being  missed  when  harvesting. 
Protected  fruits  nearing  maturity  on  the  tree  are  shown  in  Fig.  3  from 
a  photograph  taken  in  August. 

SOME  GENERAL  CONSIDERATIONS  REGARDING  RESULTS  OF  POLLINATIONS 

Flowers  are  emasculated,  pollen  applied  to  stigmas,  and  every 
detail  in  the  process  carefully  and  thoughtfully  executed.     What  will 


FIG.   3. — CHEESECLOTH   BAGS 

PROTECTING  APPLE  CROSSES 

ON  A  ROE'S  DUCHESS 

TREE 

These  cheescloth  bags  re- 
place the  paper  bags  after 
it  is  determined  that  fruit 
is  developing,  and  are  left 
on  until  the  fruit  is  mature. 
This  photograph  was  taken 
in  August,  when  the  fruit 
was  nearly  mature. 


354  BULLETIN  No.  275  [June, 

be  the  result?  Presumably,  in  each  case  pollen  tubes  will  grow, 
descend  the  styles  to  the  nucleus  within  the  ovary,  fertilization  occur, 
and  the  ovary  develop  into  a  fruit  containing  seeds  from  which  will 
come  the  next  generation.  If  this  sequence  of  events  were  universal, 
and  viable  seeds  resulted  from  each  transfer  of  pollen,  the  labor  of  the 
plant-breeder  would  be  much  simplified.  But  results  .are  frequently 
disappointing;  laborious  preparation  of  flowers  and  the  utmost  care 
in  succeeding  operations  are  often  attended  with  complete  failure,  or 
a  very  unsatisfactory  percentage  of  success. 

Where  success  does  not  attend  efforts  to  hybridize,  questions 
regarding  reasons  for  failure  naturally  arise.  The  problems  pre- 
sented cover  the  full  range  of  plant  activities;  they  are  complex  and 
do  not  admit  ready  and  satisfactory  solution.  Attempts  to  analyze 
the  circumstances  and  conditions  under  which  the  work  was  done  find 
uncertainties  enveloping  many  important  points,  chiefly  because 
results  are  not  immediate;  weeks  or  months  may  have  elapsed  since 
the  initial  operations  were  performed,  and  memory  is  at  fault  regard- 
ing distant  details.  It  is  remembered  that  the  plants,  to  all  appear- 
ances, were  vigorous,  that  flowers  opened  normally,  stigmas  were 
properly  developed,  pollen  was  viable,  and  weather  conditions  favor- 
able. Nothing  unfavorable  to  the  formation  of  fruit  and  seeds  can  be 
recalled.  Here  enters  the  temptation  to  dismiss  the  matter  with  an 
assumption  and  conclude  that  failure  resulted  from  want  of  affinity 
between  the  plants  paired.  When  crossing  is  attempted  between 
remotely  related  plants,  as  between  varieties  of  unlike  species,  failure 
is  common ;  it  is  expected  and  appeal  to  want  of  affinity  as  a  cause  is, 
perhaps,  justified.  But  in  apple  breeding  most  of  the  combinations 
attempted  are  between  forms  that  are  much  alike.  The  disappoint- 
ment comes  when  these  similar  forms,  presumably  closely  affiliated 
botanically,  refuse  to  respond  to  efforts  to  cross  them.  This  they  fre- 
quently do  and  satisfactory  reasons  for  the  failures  are  difficult  to 
assign.  To  say  that  failure  to  produce  fruit  is  due  to  want  of  affinity 
between  the  plants  may  be  true,  but  there  is  no  proof  that  this  is  the 
cause  of  failure;  as  commonly  used,  the  expression  "want  of  affinity" 
simply  serves  as  a  convenient  cover  for  ignorance  of  the  true  reason 
for  failure. 

Repeated  trial  of  the  same  cross,  always  with  the  same  result, 
will  finally  afford  a  basis  upon  which  the  assumption  of  want  of 
affinity  may  rest,  and  the  safety  in  which  it  rests  is  in  proportion  to 
the  number  of  tests  upon  which  the  assumption  is  based. 

In  some  cases  a  plant  is  fruitful  when  the  stigmas  are  supplied 
with  one  kind  of  pollen  and  infertile  when  other  kinds  are  used;  it  is 
said  of  such  a  plant  that  it  has  affinity  for  the  accepted  pollen  and 
antipathy  for  that  refused,  or  that  it  has  a  certain  selective  power. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  355 

Here  again  only  repeated  occurrence  of  the  same  phenomenon  gives 
warrant  for  the  conclusion  that  the  plant  is  habitually  sterile  with 
one  kind  of  pollen  and  fertile  with  another. 

There  are  seasonal  differences  in  plants,  differences  in  general 
vigor  that  react,  in  conjunction  with  atmospheric  or  other  surrounding 
conditions  prevailing  at  the  time  pollination  is  performed,  in  a  way 
that  may  affect  the  result  one  way  or  the  other.  This  may  be  illus- 
trated by  reference  to  an  experience  with  an  attempted  cross  between 
two  varieties.  Domine  pollen,  used  on  57  flowers  of  Winter  Rambo 
in  1909,  gave  no  fruits;  47  flowers  on  the  same  tree  of  Winter  Rambo 
pollinated  in  1911  with  pollen  from  the  same  tree  that  supplied  pollen 
in  1909,  gave  no  fruits, — complete  failure  in  two  seasons.  The  sus- 
picion seemed  warranted  that  here  was  a  case  of  habitual  refusal  on 
the  part  of  Winter  Rambo  to  accept  Domine  pollen,  but  in  1913  mating 
the  same  individuals  in  the  same  way  gave  7  fruits  with  perfect  seeds 
from  47  pollinations.  No  better  conditions  prevailed  at  flowering 
time  in  1913  than  in  the  years  when  complete  failure  resulted;  there 
were  no  evidences  of  differences  in  vigor  of  the  trees,  and  the  manual 
operations  in  the  different  years  were  performed  with  equal  care.  The 
percentage  of  successful  pollinations  in  1913  was  small,  but  sufficient 
to  show  that  the  suspicion  of  habitual  sterility  as  applied  to  this  cross 
was  not  well  founded  and  that  causes  for  the  earlier  failures  rested  on 
some  other  factor  or  factors  not  determined. 

In  breeding  practice  it  is  not  uncommon  to  encounter  marked 
differences  between  individuals  of  the  same  variety  or  of  the  same 
strain,  and  for  this  reason  the  behavior  of  a  single  individual  for  a 
single  season  does  not  afford  secure  foundation  for  a  definite  asser- 
tion regarding  the  fertility  or  sterility  of  the  variety  or  strain  when 
used  in  any  particular  combination.  Failures  are  not  confined  to 
those  combinations  undertaken  with  expectancy  of  failure;  they  as 
frequently  occur  where  success  was  confidently  expected,  and  any 
study  into  causes  soon  brings  the  conviction  that  the  factors  which, 
singly  or  in  combination,  influence  the  results  of  pollination,  are  many 
and  various.  In  some  cases  adverse  results  are  readily  and  confidently 
ascribed  to  a  definite  cause,  as  when  frost  at  time  of  pollination 
blackens  styles;  here  is  something  tangible  and  easily  detected  by 
observation.  In  other  cases  there  is  difficulty,  often  amounting  to 
impossibility,  in  isolating  the  active  factor  among  several,  any  one  of 
which  may  have  been  directly  responsible  for  the  observed  results. 
In  still  other  cases  nothing  is  discoverable  in  ancestry,  relationship, 
environment,  atmospheric  conditions,  structure,  or  appearance  that 
affords  tangible  support  for  any  theory  of  causes  that  may  be  con- 
ceived. Plants  sometimes  exhibit  a  coyness  or  perversity  that  is 
unaccountable  and  exasperating. 


356  BULLETIN  No.  275  [June, 

SOME  OF  THE  CAUSES  OF  FAILURES  OF  POLLINATIONS 

The  causes  of  failures  of  pollination  are  so  numerous  that  to 
assign  failure  definitely  to  one  of  them  is  practically  impossible.  Some 
of  these  causes  are  open,  easily  observed,  and  their  connection  with 
particular  failures  may  be  confidently  asserted;  others  are  obscure, 
not  readily  separable  as  units,  often  operating  with  others,  and  their 
relation  to  results  is  more  frequently  assumed  than  definitely  known. 

Botanical  Relationship. — Failure  is  the  rule  when  crossing  is 
attempted  between  plants  not  closely  related  botanically;  there  are 
exceptions,  but  in  a  broad  way  the  rule  applies.  The  Malus  forms  in 
the  collection  represent  several  well-defined  species,  a  number  of 
undoubted  hybrids,  and  considerable  range  of  varieties,  but  uncertain- 
ties attach  to  the  relationship  of  most  of  them — uncertainties  which,  in 
the  absence  of  historical  data,  can  never  be  eliminated  unless  light 
is  thrown  upon  them  thru  systematic  breeding.  The  forms  are  various ; 
they  differ  in  habit  of  growth,  in  foliage,  flower,  and  fruit,  and  yet 
most  of  them  hybridize  readily  among  themselves  and  with  orchard 
varieties. 

The  extremes  of  form  may  be  represented,  perhaps,  by  the  dwarf, 
spreading  form  of  Malus  toringo  (19664),  a  plant  low  in  stature, 
with  lobed  leaves  and  fruits  no  larger  than  peas,  on  the  one  hand, 
and  Grimes  or  other  orchard  varieties  on  the  other.  From  appearance 
of  plants  and  their  fruits,  the  collection  offers  no  more  violent  cross 
than  that  between  this  dwarf  Malus  and  any  one  of  several  varieties 
of  the  common  apple.  But  these  matings  have  been  fairly  successful 
in  fruit-production;  thus  29  flowers  of  toringo  pollinated  by  Grimes 
yielded  18  fruits,  or  62  percent  of  the  pollinations  successful;  16 
flowers  pollinated  by  Winter  Rambo  yielded  15  fruits,  a  success  per- 
centage of  93.75;  158  flowers  pollinated  by  Oldenburg  yielded  32 
fruits,  a  percentage  of  20.25;  29  flowers  pollinated  by  Stayman  Wine- 
sap  yielded  no  fruits.  The  latter  was  the  only  one  of  eight  varieties 
used  as  pollen  parents  that  failed,  and  the  lowest  percentage  attained 
by  the  other  seven  is  that  given  for  Oldenburg.  The  behavior  of  these 
plants  points  to  a  nearer  botanical  relationship  than  is  indicated  by  the 
appearance  of  the  plants  or  of  their  fruits. 

Want  of  Affinity. — If  two  plants  cross  readily  it  is  said  that  they 
have  affinity  for  each  other;  if,  of  two  similar  plants,  one  refuses  to 
be  fertilized  by  pollen  from  the  other,  the  phenomenon  is  referred  to 
as  the  expression  of  an  antipathy  of  the  one  plant  against  the  other. 
In  the  first  case  the  habitual  success  of  pollination  is  evidence  that 
the  two  plants  accord  in  structure  and  function,  and  the  term  affinity 
expresses  the  relation.  In  the  second  case  there  is  the  evidence  of 
failure  that  in  some  undiscovered  particular  the  two  plants  are  not  in 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  357 

accord;  usually  the  reason  for  failure  is  not  determined  and  it  is  con- 
venient to  say  that  there  is  antipathy  between  the  plants. 

It  is  believed  that  in  each  case  of  habitual  refusal  to  cross  there 
is  a  definite  reason  for  the  failure,  and  it  seems  probable  that  examina- 
tion, in  detail,  of  floral  organs,  and  close  inquiry  into  all  circumstances 
attending  pollination  would  lead  to  discovery  of  facts  that  would 
admit  less  indefinite  assignment  of  the  causes  of  refusal  to  cross  than 
to  assume  that  it  rests  in  an  antipathy.  Such  inquiries  are  important; 
they  are  in  the  nature  of  special  problems  that  can  be  undertaken  only 
when  assigned  singly  to  capable  men  who  can  be  given  all  the  time 
and  equipment  necessary  to  carry  the  problems  to  successful 
conclusions. 

Impaired  Vigor  of  One  or  Both  Parent  Plants. — Reference  is  made 
here  to  such  possible  impairment  of  vigor  as  may  result  from  starva- 
tion, drouth,  excessive  moisture,  or  other  adverse  conditions  to  which 
the  plants  may  have  been  subjected  during  the  period  of  bud  forma- 
tion. Such  impairment  may  be  a  cause  of  failure  of  pollinations,  but 
assignment  of  failure  to  such  causes  must  be  attended  with  certain 
elements  of  uncertainty,  because  of  the  practical  impossibility  of 
establishing,  in  definite  manner,  the  connection  between  the  forces 
acting  in  one  season,  and  the  results  attained  in  the  next. 

Injury  from  Winter  Cold. — Low  temperatures  in  winter  are  more 
frequently  destructive  to  pistils  than  to  stamens.  The  injury  is  easily 
detected  when  severe  enough  to  blacken  stigmas,  but  winter  cold  is 
frequently  suggested  as  a  cause  of  failure  to  fertilize  in  cases  where 
flowers  open  normally  and  stigmas  appear  healthy.  It  is  not  unreason- 
able to  assume  that  there  may  be  injury  to  floral  parts,  but  a  certain 
degree  of  uncertainty  must  attach  in  such  cases;  the  injury  is  assumed 
rather  than  proved. 

Injury  from  Spring  Frosts. — Styles  and  stigmas  are  delicate 
organs.  When  denuded  of  the  protective  bud  scales  and  fully  exposed 
by  expansion  of  the  floral  envelope  they  are  open  to  injury  by  frosts, 
which  may  cause  failure  by  preventing  fertilization,  or  may  kill  the 
ovary  after  fertilization  has  taken  place.  Spring  frosts  as  causes  of 
failure  of  pollinations  are  definite.  They  come  at  times  when  blos- 
soms are  receiving  attention,  effects  are  subjected  to  critical  examina- 
tion, and  assignment  of  failure  to  this  cause  is,  usually,  made  quickly 
and  positively. 

Cold  Rains  and  Wind. — Cold  rains  when  protracted  and  accom- 
panied by  high  winds  may  so  injure  pistils  as  to  prevent  fertilization, 
and  the  vitality  of  pollen  sometimes  appears  to  be  injured  by  these 
agencies.  Often  flowers  are  whipped  about  by  winds  in  such  manner 
as  to  cause  mechanical  injuries.  In  some  seasons  failures  from  this 
cause  are  many. 


358  BULLETIN  No.  275  [June, 

Imperfect  Pollen. — Apple  trees  in  the  adolescent  state  commonly 
flower  for  one  or  two  years  without  producing  fruit.  The  vegetative 
function  is  still  ascendant,  and  adjustment  of  balance  with  the  repro- 
ductive function  has  not  been  perfected.  The  flowers  appear  nomal, 
but  produce  stamens  whose  anthers  do  not  dehisce  normally,  and 
which  are  either  empty  or  partially  filled  with  pollen  so  imperfectly 
formed  as  to  be  incapable  of  performing  its  proper  functions.  Imper- 
fect pollen  also  occurs  in  flowers  of  mature  trees.  Some  varieties,  in 
some  years,  have  so  large  a  proportion  of  defective  grains  that  use  of 
the  pollen  invariably  results  either  in  entire  failure  or  in  a  very  low 
percentage  of  success.  The  low  record  of  Stayman  Winesap  is  due  to 
defective  pollen.  This  variety  has  been  used  as  the  pollen  parent  in 
twenty-four  crosses,  on  nineteen  forms  of  Malus  that  have  involved 
559  pollinations.  Thirteen  of  the  crosses,  involving  197  pollinations, 
failed  entirely;  one  cross,  with  6  pollinations,  yielded  2  fruits  con- 
taining no  seeds;  four  crosses,  involving  200  pollinations,  yielded  5 
fruits  containing  10  seeds,  none  of  which  germinated;  two  crosses, 
with  111  pollinations,  yielded  38  fruits  containing  49  seeds,  9  of  which 
germinated,  but  the  seedlings  died  very  soon  after  appearance  above 
ground;  one  cross,  with  21  pollinations,  yielded  8  fruits  with  27  seeds, 
14  of  which  germinated;  nine  seedlings  were  moved  to  nursery,  but 
the  last  one  died  before  the  end  of  the  fourth  year.  Thus  twenty-one 
of  the  twenty-four  crosses  are  eliminated;  the  other  three,  with  84 
pollinations,  yielded  26  fruits  containing  54  seeds,  25  of  which  ger- 
minated; eleven  seedlings  are  now  living  at  nine  years  of  age;  three 
of  the  seedlings  are  doubtfully  graded  as  good,  four  as  fair,  and  four 
as  poor. 

One  of  the  crab-like  forms  of  Malus  that  came  to  the  collection 
as  Malus  ringo  sublobata  never  produces  any  viable  pollen;  the 
anthers  are  small,  do  not  dehisce,  and  when  broken  up  mechanically 
yield  none  but  defective  grains  of  pollen. 

Accidents. — During  the  period  between  pollination  and  maturity 
of  fruit,  accidents  are  likely  to  occur,  often  in  sufficient  numbers  to 
increase  materially  the  percentage  of  failures.  Fruit  spurs  are  easily 
broken  and  individual  flowers  are  often  injured  by  improperly  adjusted 
bags.  Some  accidents  are  due  to  storms  and  wind  and  are  unavoid- 
able, but  the  number  that  occur  can  be  reduced  by  careful  selection 
of  clusters  to  be  pollinated  and  by  extreme  care  in  the  performance 
of  all  operations.  In  a  few  cases  failures  have  been  definitely  traced 
to  injuries  inflicted  by  the  tool  used  in  emasculating;  in  other 
cases  this  cause  was  suspected  but  could  not  be  proved  because  the 
evidence  of  injury  had  been  destroyed  by  drying  out  before  the  time 
of  examination. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  359 

THE  PLANT  BREEDING  HOUSE 

The  pollination  work  thus  far  referred  to  has  applied  only  to 
work  done  in  the  orchard.  This  has  been  attended  with  much  discom- 
fort and  many  disappointing  results;  it  comes  at  a  season  when  fluc- 
tuations in  weather  are  often  sudden  and  severe,  when  high  winds  are 
common,  showers  frequent,  and  temperatures  often  low.  Emasculation 
and  pollination  have  been  attempted  when  fingers  were  so  numb  that 
the  bags  were  tied  with  difficulty  and  the  other  more  delicate  operations 
performed  in  a  very  unsatisfactory  manner.  Repeated  discouraging 
experiences  led  to  a  request  for  a  glass  house  in  which  trees  could  be 
brought  to  flower  and  where  the  work  of  pollination  could  be  carried 
on  under  perfectly  controlled  conditions  of  temperature  and  moisture. 

The  Department  of  Horticulture  had  two  greenhouses,  each 
20  by  50  feet,  that  had  been  constructed  for  floricultural  work.  These 
were  fitted  with  permanent  benches,  having  low  side-walls,  and  were 
well  adapted  to  the  culture'  of  small  plants  but  not  suitable  for  the 
growth  of  fruit  trees. 

When  construction  of  a  new  house  was  authorized,  search  was 
made  for  a  model  with  high  side-walls,  something  that  would  fill  the 
needs  as  then  understood,  but  nothing  could  be  found  and  finally  plans 
were  drawn  that  were  modeled  in  part  after  a  description  of  a  green- 
house in  use  at  the  German  Experiment  Station  at  Bernburg  as  given 
by  Professor  Helriegel  in  the  Experiment  Station  Record  for  Febru- 
ary, 1894. 

Construction  was  begun  early  in  the  summer  of  1912  and  the  house 
was  ready  for  occupancy  by  the  end  of  the  year.  As  built,  the  plant 
consists  of  the  main  glass  house  30  by  80  feet,  to  which  is  joined,  on 
the  west  at  the  north  end,  a  forcing  house  28  by  80  feet,  which  extends 
to  a  cross  house  or  glass-covered  corridor  connecting  with  the  service 
building  at  the  north  and  affording  exit  to  the  yard  on  the  south.  At 
the  south  end  of  the  larger  glass  house  is  a  wire-covered  steel  frame 
house  of  the  same  height  and  floor  space  as  the  glass  house.  The  side- 
walls  of  the  larger  glass  house  consist  of  10  feet  of  glass  resting  upon 
a  concrete  foundation  wall  2  feet  high;  the  glass  portion  is  divided 
midway  by  a  horizontal  bar  to  which  the  lower  sashes,  each  5  feet 
wide  by  8^  feet  long,  are  hinged  as  ventilators.  There  are  five  of 
these  vents  on  the  west  and  nine  on  the  east  side,  besides  one  of  half 
the  standard  length  on  each  side.  At  the  apex  of  the  roof  on  each 
side  are  nine  ventilators,  each  3  feet  wide  and  8^3  feet  long,  and  also 
one  of  half  the  standard  length;  all  ventilators  are  controlled  by  ven- 
tilating machines  which  operate  from  the  side-walls,  thus  leaving  the 
floor  space  clear  of  supports.  At  each  end  are  six  doors  arranged  in 
three  pairs;  each  door  is  3%  feet  wide  by  12  feet  high,  thus  opening 
almost  the  entire  ends  from  the  concrete  sill  at  the  floor  level  to  the 
full  height  of  the  side-walls.  The  heavy  hinges  are  bolted  to  the 


360  BULLETIN  No.  275  [June, 

upright  steel  division  bars  which  do  not  allow  sagging,  and  the  doors 
open  easily.  The  ventilation  facilities  allow  that  degree  of  openness 
that  is  necessary  during  the  still,  clear  days  in  early  spring  when 
action  of  the  sun  on  the  glass  roof  elevates  inside  temperature  beyond 
the  limit  that  is  best  for  the  trees. 

Heating  pipes  are  arranged  against  the  concrete  side-walls  and 
at  each  end;  between  the  pairs  of  doors  are  two  radiators  for  use  in 


FIG.  4. — PLANT  BREEDING  GREENHOUSE  AND  PORTIONS  OF  ADJOINING  HOUSES 
This  house  was  constructed  in  1912.  The  high  side-walls  are  an  essen- 
tial feature  of  the  building. 

emergency.  No  benches  are  used  but  all  trees  grown  in  the  house  are 
in  pots  which  are  plunged  in  rows  as  convenient. 

The  smaller  glass  house  has  concrete  side-walls  31/2  feet  high  upon 
which  rests  the  glass  walls  2^2  feet  high;  these  are  hung  in  sections, 
the  entire  length  on  both  sides.  The  ventilators  and  the  roof  ventila- 
tors are  the  same  as  provided  in  the  larger  house. 

The  wire  house  built  as  an  extension  to  the  larger  glass  house 
consists  of  a  steel  frame  over  which  wire  screen  of  i/o-inch  mesh  is 
placed.  This  is  used  as  a  safe  shelter  for  plants  which  are  moved  out 
from  the  glass  house  after  danger  of  frost  is  past.  The  pots  containing 
the  trees  are  plunged  as  in  the  glass  house.  Here  the  fruits  resulting 
from  early  spring  pollinations  are  brought  to  maturity  protected  from 
birds  and  from  severe  winds.  Fig.  4  is  from  a  photograph  of  the 
main  house  with  portions  of  the  attached  houses,  taken  October  25. 
Interiors  of  the  glass  house  in  spring  and  the  wire  house  in  summer 
are  shown  in  Figs.  5  and  6. 

Eleven  years'  experience  with  the  structures  described  has  sug- 
gested no  material  change  in  construction;  they  have  proved  very 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


361 


satisfactory  in  all  respects.    The  steel  frames  are  so  constructed  that 
there  is  little  interference  with  light;  they  are  strong  and  of  pleasing 


FIG.  5. — INTERIOR   OF   PLANT   BREEDING   GREEN- 
HOUSE, MARCH  15 

Concrete  foundation  walls  2  feet  high  support  10 
feet  of  glass,  portions  of  which  are  hinged  and  serve 
as  ventilators.  Ventilators  in  the  roof  are  controlled 
by  machines  which  operate  from  the  side-walls,  thus 
leaving  the  floor  space  clear  of  supports. 

lines.  Floor  space  is  unobstructed  by  supports,  allowing  convenient 
arrangement  of  plants,  which  may  be  changed  at  will  to  suit  cir- 
cumstances. 

The  operations  of  emasculation  and  pollination  are  done  in  the 
house,  not  only  more  comfortably  but  with  greater  accuracy  than  'is 
possible  when  perched  on  a  ladder  among  the  branches  of  orchard 
trees,  particularly  when  winds  are  blowing  and  temperatures  are  low. 
The  small,  potted  trees  are  easily  moved  about  and  can  be  placed  in 
positions  most  convenient  for  working  on  particular  clusters.  The 
operator  may  sit  comfortably,  with  a  stand  at  hand  for  record  and 


362  BULLETIN  No.  275  [June, 

tools,  and  thus  be  able  to  concentrate  his  energies  and  perform  the 
work  in  the  best  possible  manner.  The  danger  of  contamination  by 
undesired  pollen  is  reduced  to  a  minimum ;  there  are  no  accidents  from 
wind  and  rain  and  a  much  higher  percentage  of  success  is  attained 
than  is  possible  when  the  work  is  done  in  the  open  orchard. 

This  is  not  to  say  that  no  failures  occur  in  pollination  under 
glass;  failures  do  occur,  sometimes  many  of  them;  certain  combina- 
tions attempted  either  fail  entirely,  or  give  only  a  low  percentage  of 


FIG.  6. — INTERIOR  OF  THE  WIRE  HOUSE  SHOWN  IN  FIG.  4  AT 

THE  RIGHT  OF  THE  MAIN  HOUSE 

Plants  moved  out  from  the  main  house  after  danger  of  frost  is  past 
&re  sheltered  here.  The  fruits  resulting  from  early  spring  pollinations  are 
brought  to  maturity  protected  from  birds  and  severe  winds. 

success  whether  the  work  is  done  under  glass  or  in  the  orchard.  In 
these  cases  the  difficulties  lie  with  the  plants  themselves,  and  the 
causes  of  failure  have  nothing  to  do  with  surrounding  conditions. 
Some  plants  are  habitually  poor  breeders,  and  improvement  in  con- 
ditions under  which  the  work  is  done  does  not  effect  a  corresponding 
improvement  in  breeding  results.  Comparisons  of  particular  com- 
binations made  both  in  the  orchard  and  under  glass  almost  invariably 
show  much  better  results  where  conditions  are  controlled  than  where 
the  work  is  done  in  the  open. 

COLLECTING  TREES  FOR  FORCING  PURPOSES 
In  anticipation  of  the  construction  of  a  greenhouse,  the  prepara- 
tion of  plants  was  begun  in  the  spring  of  1910.    Paradise  and  Doucin 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  363 

stocks  were  potted  in  8-inch  pots  and  grafted  with  scions  from  avail- 
able species  of  Malus  and  from  orchard  varieties.  Additions  were 
made  in  1911,  including  a  few  plants  grafted  with  scions  from  hybrids 
from  crosses  of  1909.  The  pots  were  plunged  outside  in  summer;  late 
in  the  fall  they  were  bunched  together  and  mulched  to  guard  against 
too  severe  freezing,  and  in  January,  1913,  were  brought  into  the  house 
and  kept  under  moderate  heat.  There  were  95  trees  in  all,  represent- 
ing 46  crab-like  forms  of  Malus,  19  orchard  varieties,  and  7  hybrids 
from  crosses  made  in  1909.  Fourteen  of  the  forms  of  Malus  and  one 
orchard  variety  bloomed  in  March,  and  567  flowers  were  pollinated 
and  yielded  173  fruits;  a  ratio  of  fruits  to  pollinations  of  1  to  3.27. 
Four  of  the  combinations  attempted,  involving  43  flowers,  failed 
entirely.  The  remaining  fifteen  combinations  gave  percentages  of 
success  ranging  from  3  to  98.  The  highest  percentage  was  attained  in 
crossing  Malus  baccata  oblonga  (811)  by  Yellow  Transparent;  49 
flowers  pollinated  gave  48  fruits  yielding  319  seeds,  100  of  which  ger- 
minated, and  33  trees,  now  ten  years  old,  are  living.  Owing  to  the 
small  amount  of  bloom  in  this  first  season  of  work  under  glass,  some 
difficulty  was  experienced  in  obtaining  pollen  of  desired  kinds  at  the 
time  when  wanted,  and  in  consequence  some  of  the  matings  were  such 
as  would  not  have  been  chosen  had  pollen  of  other  kinds  been  avail- 
able. All  that  could  be  done  was  to  utilize  such  pollen  as  could  be 
obtained. 

In  succeeding  seasons,  with  increased  numbers  of  trees  and  many 
more  trees  flowering,  the  difficulty  of  obtaining  desired  pollen  became 
less  and  in  the  spring  of  1916  disappeared;  there  were  then,  and 
have  been  in  later  seasons,  more  flowers  produced  than  could  be  util- 
ized, and  there  has  been  little  difficulty  in  obtaining  pollen  of  the  kind 
and  at  the  time  wanted.  Last  season  there  were  in  the  houses  573  trees, 
which  classify  as  407  hybrids,  86  representing  46  forms  of  Malus  and 
80  representing  35  orchard  varieties.  On  these  plants  169  crosses 
involving  2,151  pollinations  were  made,  and  471  fruits  were  harvested. 
The  success  percentage  is  21.89,  which  is  quite  low,  owing  to  an 
unusual  number  of  attempted  crosses  that  failed  entirely. 

The  houses  are  now  filled  to  capacity  and  the  trees  flower 
abundantly  each  spring.  That  they  succeed  reasonably  well  on  dwarf 
stocks  is  evidenced  by  the  fact  that  there  are  living  in  the  house  60 
trees  that  were  grafted  in  the  spring  of  1910  and  are  now  fourteen 
years  old. 

In  grafting  hybrids  on  dwarf  stocks  the  expectation  was  that 
earlier  fruiting  would  be  induced  and  thus  hasten  the  starting  of  the 
second  generation,  but  thus  far  experience  in  this  direction  has  been 
somewhat  disappointing.  Of  seven  trees  from  scions  of  hybrids  of 
1909,  grafted  in  the  spring  of  1911,  one  that  fruited  in  1916  at  six 
years  from  graft  has  fruited  each  year  since  and  appears  as  a  parent  in 


364  BULLETIN  No.  275  [June, 

a  number  of  second-generation  crosses.  Two  other  trees  fruited  for 
the  first  time  in  1918,  one  in  1919,  and  one  in  1922.  There  are  still  two 
trees  that  altho  thirteen  years  from  graft  have  not  yet  flowered  or 
fruited. 

This  record  is  very  little  better  than  the  record  of  the  seedlings 
in  orchard.  In  the  house  as  dwarfs,  one  of  seven  fruited  in  the  sixth 
year,  while  in  the  orchard  one  of  ten  seedlings  fruited  in  the  sixth 
year.  Not  one  of  the  seedlings  from  which  scions  were  taken  flowered, 
but  for  five  of  the  seven  trees  in  the  house  there  were  sister  trees  in 
the  orchard  that  did  flower;  that  is,  other  individuals  from  seeds  of 
the  same  fruit.  The  paradise  stocks  on  which  the  scions  were  grafted 
were  of  French  origin,  and  while  nothing  is  known  of  the  particular 
strain  of  Malus  from  which  they  came,  it  has  appeared  that  they 
exercised  the  dwarfing  influence  on  scion  growth  that  is  commonly 
associated  with  paradise  stocks.  They  do  not  in  this  case,  however, 
appear  to  have  exercised  any  influence  in  the  direction  of  earlier  fruit 
production. 

COLLECTING  BREEDING  MATERIAL 

ORCHARD  VARIETIES 
Trees  Available  in  1907 

When  apple  breeding  was  commenced  in  1907  the  departmental 
orchards  of  bearing  trees,  which  had  been  seriously  depleted  by  neces- 
sary extensions  of  the  University  campus,  consisted  of  two  blocks  or 
plats:  Plat  A  with  141  trees  representing  102  varieties,  a  large  pro- 
portion of  which  were  of  Russian  origin,  and  Plat  C  with  119  trees 
representing  28  varieties,  most  of  which  were  such  as  are  commonly 
planted  in  Illinois  orchards. 

Two  rows  of  younger  trees  in  Plat  D,  with  19  trees  of  13  varieties 
not  elsewhere  represented  and  including  Ingram,  Beach  (Apple  of 
Commerce),  Springdale,  Oliver,  Fanny,  and  Arkansas  (Mammoth 
Black  Twig),  began  flowering  in  1911  and  in  that  and  the  two  follow- 
ing years  were  used  to  some  extent,  so  that  part  of  these  varieties 
appear  in  the  list  of  varieties  used  as  parents,  but  in  the  fall  of  1913 
these  trees  were  removed. 

In  1904  a  tract  of  approximately  ten  acres  was  planted  with 
306  trees  representing  seven  varieties;  namely,  Jonathan,  Ben  Davis, 
Oliver,  Black  Ben  Davis,  Jefferis,  Grimes,  and  Collins.  This  is  known 
as  the  "Commercial  Orchard."  The  trees  began  flowering  in  1913 
and,  in  the  years  since  then,  selected  individuals  have  been  used  as 
parents  in  breeding. 

Additions  Since  1907 

It  was  foreseen  in  1907,  at  the  time  apple  breeding  was  begun, 
that  the  two  plats  of  bearing  trees  would  be  absorbed  in  campus 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  365 

extensions  within  a  few  years  and  that  it  would  be  necessary,  in  order 
to  provide  trees  for  use  in  continuation  of  the  breeding  projects  under- 
taken, to  secure  other  areas  so  situated  as  to  insure  permanency  of 
plantations  made,  and  then  to  plant  these  areas  with  the  varieties 
desired  for  breeding  purposes.  No  land  was  available  at  this  time, 
but  it  was  thought  best  to  buy  the  trees  and  hold  them  in  the  nursery 
until  such  time  as  land  could  be  obtained  for  orchard  purposes. 

To  this  end  a  list  was  made  which  included  varieties  known  to 
have  been  thoroly  tested  in  the  state,  which  had  received  the  endorse- 
ment of  the  State  Horticultural  Society.  To  this  were  added  a  few 
varieties,  such  as  Baldwin,  King,  and  Rhode  Island  Greening,  not 
commonly  planted  in  Illinois  but  desired  as  part  of  a  breeding 
collection.  The  list,  which  included  37  varieties,  follows: 

Summer  Autumn 

Benoni  Oldenburg  Chenango  Mclntosh 

Bough  Red  Astrachan  Dyer  McMahon 

Early  Harvest  Red  June  Fameuse  Mother 

Golden  Sweet  Sops  of  Wine  Longfield  Ramsdell  Sweet 

Keswick  Yellow  Transparent  Maiden  Blush  Wealthy 

Winter 

Baldwin  King  Pewaukee  Tolman 

Ben  Davis  Minkler  Rails  Westfield 

Domine  Northern  Spy  Rhode  Island  Wellow 

Grimes  Northwestern  Greening  Winesap 

Jonathan  Greening  Salome 

Copies  of  this  list  were  sent,  with  orders  for  one  tree  of  each 
variety,  to  nine  nurseries:  one  in  Canada,  the  others  distributed  in 
seven  states  from  Maryland  to  Kansas. 

This  distribution  of  prospective  parent  trees  was  adopted  in  order 
that  trees  of  the  same  variety  from  widely  separated  localities  might 
be  grown  contiguously  for  convenience  of  observation,  for  the  purpose 
of  determining  whether  or  not  there  exist  tangible  differences  indicat- 
ing well-defined  strains  in  any  or  all  the  varieties.  Incidentally,  oppor- 
tunity was  offered  for  direct  comparison  of  trees  grown  in  nurseries 
remote  from  each  other  with  markedly  different  soils  and  under  differ- 
ent climatic  conditions.  This  comparison  proved  interesting  and 
showed  very  conclusively  that  there  are  decided  differences  in  nursery 
trees  from  different  sections.  These  differences  were  most  apparent 
in  color  of  bark,  in  size,  and,  most  important,  in  root  systems. 

The  trees  were  all  two  years  from  graft  or  bud,  and  when  those 
from  different  sources  were  placed  side  by  side,  whether  compared  by 
single  varieties  or  by  entire  lots,  the  differences  in  most  cases  were 
constant.  Naturally  there  were,  in  the  nine  groups  of  trees,  extremes 
and  intermediates.  Here  were  two  lots  that  illustrated  the  extremes: 
one  lot  with  trees  all  below  medium  in  size  for  two-year-old  trees,  the 


366  BULLETIN  No.  275  [June, 

bark  light  in  color  and  dull,  and  the  roots  consisting  of  a  few  short 
stubs  with  few  or  no  fibrous  roots ;  the  other  lot  of  the  same  age  con- 
sisting of  trees  above  medium  in  size  and  yet  not  having  the  appear- 
ance of  overgrown  trees,  bark  bright,  of  decidedly  darker  color,  and 
the  root  systems  masses  of  small  roots  abundantly  supplied  with 
fibrous  roots.  Manifestly  the  two  lots  of  trees  were  grown  on  very 
different  soils.  The  small  trees  with  no  small  roots  were  grown  on 
infertile  soil  that  made  it  necessary  for  the  trees  to  forage  at  a  dis- 
tance for  food  and  extend  the  roots  so  that  most  of  them  were  left  in 
the  ground  when  the  trees  were  dug.  The  other  lot,  on  soil  of  abundant 
fertility  which  was  near  at  hand  and  readily  available,  produced 
masses  of  small  roots  immediately  about  the  central  roots,  and  these 
masses  went  with  the  trees  when  they  were  removed. 

No  one  called  upon  to  choose  between  the  two  lots  of  trees  would 
hesitate  in  accepting  the  large  trees  with  abundant  roots  as  best.  When 
planted,  these  trees  started  growth  earlier  and  with  more  vigor  than 
did  those  with  deficient  root  systems.  This  advantage  gained  in  the 
early  years  has  been  generally  maintained;  there  are,  however,  some 
cases  in  which  small  trees  with  few  roots  have  appeared  to  increase 
in  vigor  with  age  and  are  now  equal  in  growth  with  those  which  were 
most  vigorous  when  planted.  Records  of  these  trees  have  been  main- 
tained and  their  fruiting  qualities,  differences  within  varieties,  and 
evidences  of  definite  strains  will  be  given  attenton  in  a  future  paper. 

Not  all  the  trees  ordered  were  received.  The  complete  list  of  37 
varieties  would  have  given  333  trees,  but  only  218,  or  approximately 
Q5l/2  percent  of  the  number  ordered,  were  received.  Not  one  of  the 
nurseries  was  able  to  fill  the  complete  list.  One  variety,  Dyer,  was 
not  in  stock  in  any  of  the  nurseries  and  hence  was  dropped  from  the 
list.  Mother  was  received  from  only  one  nursery,  and  the  same  is 
true  of  Westfield.  Only  two  of  the  nurseries  could  supply  Ramsdell 
Sweet  and  Willow;  only  three  supplied  McMahon  and  Keswick;  four 
nurseries,  Benoni,  Golden  Sweet,  Sops  of  Wine,  and  Mclntosh;  five 
supplied  Longfield  and  Domine;  six  supplied  Bough,  Red  June,  Che- 
nango,  Minkler,  Rails,  Rhode  Island  Greening,  and  Salome;  seven 
supplied  Early  Harvest,  King,  Northern  Spy,  Pewaukee,  and  Tolman ; 
eight  supplied  Maiden  Blush,  Wealthy,  Baldwin,  Jonathan,  and 
Northwestern  Greening.  All  the  nurseries  supplied  the  following  7 
varieties:  Oldenburg,  Red  Astrachan,  Yellow  Transparent,  Fameuse, 
Ben  Davis,  Grimes,  and  Winesap. 

The  nurseries  were  rather  widely  distributed  and  the  trees 
received  served  to  show,  for  the  varieties  here  included,  which  were 
most  frequently  and  which  least  frequently  grown.  Of  the  nine  nur- 
series, one  supplied  29  varieties;  one,  28  varieties;  two,  26  varieties 
each;  one,  23  varieties;  and  one,  13  varieties.  One  nursery  in  making 
shipment  included  one  tree  each  of  three  varieties  for  trial ;  these  were 


19S6]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  367 

Dee's  Seedling,  Kinnard,  and  Wandering  Spy.  One  of  the  lots  of 
trees  included  two  trees  of  Winesap  instead  of  one.  This  brought  the 
aggregate  of  trees  to  222  and  that  number  was  planted  in  the  nursery, 
April  19  and  20,  1907. 

It  was  expected  that  land  could  be  secured  so  that  removal  to 
orchard  could  be  made  the  following  spring,  but  this  did  not  prove 
possible  and  it  was  not  until  the  spring  of  1909  that  the  desired  land 
became  available.  The  trees  were  removed  and  planted  30  by  30 
feet  apart,  April  15  to  19,  1909.  The  number  thus  transferred  was 
198,  showing  a  loss  during  the  two  years  in  nursery  of  24  trees,  or 
nearly  11  percent.  A  few  of  the  trees  planted  in  the  nursery  did  not 
start  growth,  others  died  at  intervals,  some  from  blight  and  some 
from  other  undetermined  causes.  The  loss  included  three  trees  each  of 
Baldwin  and  Minkler,  two  each  of  Maiden  Blush,  Wealthy,  Early 
Harvest,  and  Red  June,  and  one  each  of  ten  other  varieties. 

In  addition  to  the  trees  purchased  in  1907  there  were  planted  in 
orchard  at  the  same  time  43  trees  representing  20  varieties  from 
another  station  nursery.  This  addition  consisted  of  trees  remaining 
of  a  lot  of  certain  varieties  propagated  for  other  purposes  in  1905 
from  scions  received  from  various  sources.  Some  of  these  varieties 
were  already  represented  in  the  planting,  but  the  following  were  new 
to  the  collection,  Wolf  River,  Roe's  Duchess  Seedling,  Stark,  Colum- 
bus Red,  Water,  Sweet  Bellflower,  McClellan,  Red  Stripe,  American 
Summer  Pearmain,  Higby  Sweet,  Hyat's  Wonderful,  Howard's 
Sweet,  and  Buler  (Syn  Jonathan  [of  Buler]).  Scions  of  four  addi- 
tional varieties — Akin,  Fanny,  Delicious,  and  Stay  man  Winesap — 
were  obtained  from  Mr.  George  W.  Endicott  of  Villa  Ridge  in  the 
spring  of  1908.  These  were  root-grafted  on  seedling  stocks,  grown  in 
nursery  for  that  year,  and  planted  in  orchard  with  the  other  trees  in 
the  spring  of  1909,  an  addition  of  28  trees.  To  the  orchard  varieties 
here  enumerated  may  be  added  as  a  portion  of  the  1907  purchase, 
one  tree  each  of  the  garden  crabs,  Martha,  Florence,  General  Grant, 
Soulard,  Hyslop,  and  Transcendent. 

Five  *trees  died  during  this  first  season  in  the  orchard  and  the 
vacancies  were  filled  in  the  spring  of  1910  with  Black  Ben  Davis.  One 
of  these  trees  died  and  in  the  three  following  years  seven  additional 
vacancies  occurred,  mainly  thru  attacks  by  blight.  These  vacancies 
were  filled  in  1914  with  trees  sent  to  the  Station  for  trial  by  Stark 
Brothers  of  Louisiana,  Missouri;  the  varieties  represented  by  two 
trees  each  are  Old  Wife  Pip;* in,  Ohio  Dark  Red  Rome  Beauty,  Ohio 
Nonpareil,  and  Salome,  all  but  the  latter  being  new  to  the  collection. 

Thus  this  block  of  apple  trees  planted  and  grown  especially  for 
breeding  puposes  consisted  of  269  trees  representing  64  varieties  of 
apples  and  6  crabs. 


368  BULLETIN  No.  275  [June, 

Flowering  of  the  Trees 

The  first  bloom  of  the  block  appeared  in  1912,  when  2  of  3  trees 
of  Keswick,  1  of  8  Yellow  Transparent,  2  of  6  Maiden  Blush,  1  Wan- 
dering Spy,  and  2  of  the  crabs — General  Grant  and  Florence — each 
produced  a  few  clusters ;  but  in  no  case  did  fruit  mature.  The  trees  were 
then  seven  years  old.  In  the  following  year,  1913,  the  list  of  trees  pro- 
ducing bloom  was  considerably  extended.  Of  89  trees  representing  14 
varieties,  43  are  of  record  as  having  flowers,  but  only  one  tree — one  of 
five  Longfield — had  flowers  sufficiently  perfect  and  numerous  enough 
to  warrant  its  use  in  breeding.  Forty-five  emasculated  buds  in 
twenty-five  clusters  on  this  tree  were  bagged  April  28,  1913,  and  pol- 
linated with  Jonathan  pollen  on  May  2 ;  on  June  20,  15  fruits  appeared 
to  be  developing,  but  only  10  mature  fruits  remained  at  picking  time, 
September  9.  Seedlings  .were  grown  from  seeds  of  these  fruits,  planted 
in  orchard  in  1916  and  39  of  them,  now  ten  years  old,  are  living. 
Other  trees  that  matured  fruits  in  1913  are  2  of  3  Keswick,  4  of  9 
Oldenburg,  10  of  11  Yellow  Transparent,  2  of  5  Maiden  Blush,  1  of  7 
Tolman,  1  of  7  Jonathan,  and  4  of  6  Roe's  Duchess  Seedling. 

Other  trees  began  flowering  in  the  succeeding  years,  and  in  the 
seventh  year  from  planting  in  orchard  a  number  of  trees  produced 
small  crops.  The  flowering  record  for  1916  records  88  percent  of  the 
trees  in  the  block  as  producing  flowers,  the  amount  ranging  from  a 
few  clusters  on  trees  flowering  for  the  first  time,  to  full  bloom  for  many 
that  began  flowering  in  earlier  years.  There  have  been  some  laggards, 
trees  that  were  very  tardy  in  beginning  flowering  and  did  not  reach 
full  bloom  until  they  were  far  past  the  age  at  which  bloom  should  be 
expected.  A  few  trees  altho  now  nineteen  years  old  and  growing  in 
orchard  for  fifteen  years  have  produced  no  flowers;  these  are  2  of  4 
Benoni,  2  of  6  King,  and  3  of  7  Northern  Spy.  Evidently  these  varieties 
are  not  adapted  to  conditions  in  this  locality.  Certain  individuals  in 
other  varieties  have  never  reached  satisfactory  bloom,  notably  1  of  3 
Mclntosh,  1  of  4  Golden  Sweet,  1  of  Rail's,  and  1  of  Salome;  these 
trees  have,  for  several  years,  produced  a  few  flowers  each  season,  but 
never  in  quantity  to  promise  a  crop. 

The  non-flowering  trees  are  so  evenly  distributed  with  regard  to 
region  of  origin  that  there  is  no  ground  for  suspicion  that  place  of 
origin  is  in  any  way  responsible  for  retarded  and  scant  flower  produc- 
tion, and,  except  for  the  possibility  that  they  may  be  incorrectly 
named,  there  appears  no  reason  for  their  behavior  other  than  indi- 
vidual peculiarity. 

For  several  years  this  plantation  has  had  sufficient  trees  in  fruit- 
ing condition  to  supply  all  possible  needs  of  breeding  material  of  this 
class;  there  is  wide  range  in  such  characters  as  season,  color,  size,  and 
quality.  The  combinations  that  may  be  made  for  test  of  specific 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  369 

characters  are  almost  endless,  certainly  beyond  what  it  is  desired  to 
attempt. 

SPECIES  AND  VARIETIES  OF  MALUS 
Scions  from  U.  S.  Department  of  Agriculture 

The  third  division  of  the  apple-breeding  project  covers  reciprocal 
hybrids  between  orchard  varieties  of  apples  and  such  other  species  and 
forms  of  the  genus  Malus  as  can  be  brought  to  flowering.  At  the  time 
of  beginning  breeding  work,  Whitney  and  Yellow  Siberian  Crab  were 
the  only  representatives  of  forms  other  than  orchard  varieties  and  an 
effort  was  made  to  secure  additional  kinds.  In  response  to  a  request, 
the  Bureau  of  Plant  Industry  of  the  U.  S.  Department  of  Agriculture 
very  kindly  sent  to  this  Station,  for  the  breeding  work,  a  package  of 
scions  that  had  been  presented  to  the  Department  by  Dr.  Sargent  of 
the  Arnold  Arboretum. 

This  package  contained  scions  of  sixty-two  species  and  varieties 
of  Malus  under  the  departmental  accession  numbers  19630  to  19691, 
and  was  received  January  29,  1907.  Unfortunately  the  scions,  when 
received,  were  in  such  a  dry  condition  that  it  was  believed  none  could 
live.  They  were  immersed  in  water  for  a  time  and  then  packed  away 
in  damp  sphagnum  moss  until  such  time  as  grafting  could  be  per- 
formed. 

The  list  of  forms,  with  comments,  as  received  from  the  U.  S. 
Department  of  Agriculture  was  as  follows: 

19630  to  19691  Malus  sp. 

From  Jamaica  Plain,  Mass.    Received  thru  the  Arnold  Arboretum,  Janu- 
ary 7,  1907. 

19630  Malus  sargenti,  discovered  by  Professor  Sargent  in  a  salt  marsh  near  Moro- 
nan,  Japan,  in  1892.     It  is  a  rather  small  shrub  but  very  ornamental  in 
flower. 

19631  Malus  sylvestris,  sometimes  called  M .  acerba,  and  by  the  older  botanists 
was  considered  a  form,  at  least,  of  the  common  apple. 

19632  Malus  crataegifolia,  sometimes  called  Cormus;  it  is  a  rare  Italian  tree. 

19633  Malus  spectabilis,  unknown  in  cultivation,  and  supposed  to  be  a  native  of 
China. 

19634  Malus  zumi  (not  xurui)  is  a  native  of  the  mountains  of  Japan,  where  Pro- 
fessor Sargent  found  it  in  1892  and  introduced  it  into  cultivation. 

19635  Malus  baccata  is  the  small  fruited  crab  of  eastern  Siberia. 

19636  Malus  atrosanguinea  is  probably  a  hybrid  between  M .  toringo  and  M .  flori- 
bunda. 

19637  Malus  baccata  X  Malus  X  X  (3549) 

19638  Malus  prunifolia  jrutico  coccinea 

19639  Malus  denticulata 

19640  Malus  cashmerica  is  a  Himalayan  species.    It  is  growing  well  at  the  Arnold 
Arboretum  and  is  interesting  as  one  of  the  few  Himalayan  trees  that  flour- 
ish in  this  climate. 

19641  Malus  coronaria,  the  common  species  of  the  eastern  states. 

19642  Malus  baccata  sanguinea 

19643  Malus  siberica  jrutico  coccinea 


370  BULLETIN  No.  275  [June, 

19644  Mains  microcarpa 

19645  Mains  mains,  extra  fruiting  variety 

19646  Mains  scheideckeri,  a  very  fine  seminal  form  of  the  double  M.  spectabilis 

19647  Mains  siberica.  Professor  Sargent  states  that  he  does  not  know  this,  but  it 
is  probably  a  baccata. 

19648  Mains  baccata  prunijolia 

19649  Mains  rivularis  var.    Described  by  Professor  Sargent  as  a  very  interesting 
plant  indeed,  raised  at  the  Arnold  Arboretum  from  seed  collected  many 
years  ago  in  Oregon.    It  is  quite  distinct  from  M .  rivularis  and  gives  some 
evidence  of  being  a  hybrid.    It  has  not  yet  been  described  or  named. 

19650  Mains  prunijolia,  extra  red  fruit,  is  a  Siberian  species,  according  to  Pro- 
fessor Sargent. 

19651  Mains  arnoldiana,  is  a  seedling  of  M.  floribunda  that  originated  in  the 
Arnold  Arboretum  and  shows  the  influence  of  the  blood  of  M.  prunijolia  by 
its  larger  flowers. 

19652  Mains  toringo,  is  the  common  north  China  species  with  both  red  and  yel- 
low fruits. 

19653  Mains  baccata  oblonga 

19654  Mains  toringo,  yellow  fruit 

19655  Mains  prunijolia  xanthocarpa 

19656  Mains  floribunda,  probably  a  Chinese  plant,  altho  it  was  introduced  into 
Europe  and  the  United  States  from  Japan.    It  does  not  appear  to  be  known 
in  a  wild  state. 

19657  Mains  spectabilis  var.  459-1 

19658  Mains  ringo,  probably  Japanese 

19659  Mains  spectabilis 

19660  Mains  baccata  var. 

19661  Mains  baccata  X  floribunda 

19662  Mains  ringo 

19663  Mains  baccata  aurantiaca 

19664  Mains  toringo,  a  dwarf  form  of  No.  19652  raised  at  the  arboretum  from 
Chinese  seeds. 

19665  Mains  soulardi,  the  well  known  species  or  hybrid,  as  some  authors  believe, 
of  the  Central  West 

19666  Mains  baccata  var.  Hillside,  bright  red  fruit 

19667  Mains  mains,  bright  red  fruit 

19668  Mains  rivularis,  the  common  wild  crab  of  the  Northwest 

19669  Mains  mains  444/1 

19670  Mains  aslrachanica 

19671  Mains  mains  441/2 

19672  Mains  prunijolia,  Rubia  cerasiforme 

19673  Mains  sp.  (?)  var.  Rones  crab  (Ottawa) 

19674  Mains  ioensis,  the  common  crab  of  the  Central  West 

19675  Mains  prunijolia  flava 

19676  Mains  angustifolia,  the  crab  of  the  southern  states,  getting  north  into  Mis- 
souri and  Pennsylvania 

19677  Malus  baccata  maxima 

19678  Malus  mains  X  baccata 

19679  Malus  mains  fl.  pi. 

19680  Malus  mains  jastigiata  bijera  538-2 

19681  Malus  halliana,  of  which  M .  parkmani  is  a  synonym.,  is  also  Chinese,  altho 
it  was  probably  first  introduced  from  Japan ;  it  is  unknown  in  the  wild  state. 

19682  Malus  baccata  var. 

19683  Malus  niedvoietzkyana,  a  Turkestan  tree  and  probably  a  form  of  the  com- 
mon apple. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  371 

19684  Mains  spectabilis  var.  766/1 

19685  Mains  baccata  X  toringo 

19686  Mains  ringo  incisa 
19887  Mains  kaido 

19688  Mains  pendula,  the  weeping  form  of  the  common  apple 

19689  Mains  ringo  sublobala  4645  Spath 

19690  Mains  prunifolia  macrocarpa 

19691  Mains  sp.  5004  No.  5 

Top-Grafts. — Forty-four  scions  representing  thirty-two  of  the 
serial-numbered  species  or  forms  were  top-worked  March  22,  1907. 
The  stocks  used  were  young  trees  of  Sops  of  Wine  and  Fameuse  that 
had  been  crown-grafted  on  Virginia  Crab  seedling  stocks  three  years 
previously,  and  which  were  at  this  time  growing  in  Plat  I,  5  feet  apart 
in  rows  10  feet  apart.  The  scions  were  in  very  poor  condition;  they 
had  not  recovered  from  drying  while  in  transit,  they  were  not  of 
normal  plumpness,  and  the  expectation  that  few  would  grow  was  fully 
realized. 

Only  the  following  were  living  on  October  9,  the  time  of  final 
examination  for  that  season: 

19683  Mains  niedwietzkyana 1  scion 

19651  Mains  arnoldiana '. 1  scion 

19643  Mains  siberica  frutico  coccinea 2  scions 

19670  Mains  astrachanica 1  scion 

19689  Mains  ringo  sublobata 1  scion 

19662  Mains  ringo 1  scion 

19631  Mains  sylvestris 1  scion 

The  grafts  continued  to  grow  and  serve  as  the  source  of  scions  for 
further  propagation  so  that  the  forms  listed  as  living  are  now  estab- 
lished in  the  collection  and  are  fruiting  regularly  each  season. 

Root-Grafts. — Root-grafts  on  ordinary  apple  seedling  stocks  were 
made  March  23,  1907;  sixty  of  the  sixty-two  serial  numbers  were 
represented  by  from  one  to  four  in  a  total  of  126  grafts.  These  grafts 
were  packed  in  damp  sphagnum  moss  until  April  29,  when  they  were 
planted  in  nursery.  Very  few  of  the  scions  started  growth.  When 
checked  on  July  20  only  21  grafts  representing  fourteen  serial  numbers 
were  living  and  most  of  these  were  weak.  The  living  grafts  were 
lifted  for  winter  storage  and  again  planted  in  nursery  in  the  spring  of 
1908.  When  taken  up  in  November,  1908,  16  grafts  representing 
eleven  serial  numbers  were  living;  these  were  again  grown  in  nursery 
during  1909  and  after  another  winter  in  storage  were  planted  in  the 
orchard  April  27  and  28,  1910. 

The  root-grafted  trees  thus  planted  in  orchard  were  as  follows: 

19630  Mains  sargenti 1  tree 

19644  Mains  microcarpa 2  trees 

19646  Mains  scheideckeri 1  tree 

19651  Mains  arnoldiana 1  tree 

19662  Alalus  ringo 1  tree 


372  BULLETIN  No.  275  [June, 

19664  Mains  toringo 2  trees 

19665  Mains  soulardi 1  tree 

19667  Mains  mains  var 1  tree 

19669  Mains  mains  var 2  trees 

19688  Mains  pendula 2  trees 

19689  Mains  ringo  sublobata 2  trees 

Thus  at  the  close  of  1907,  living  representatives  of  15  of  the  62 
kinds  sent  as  scions  were  divided  as  follows: 
Represented  by  root-grafts  only 

19630  Mains  sargenti  19665  Mains  soulardi 
19644  Mains  microcarpa                              19667  Mains  mains  var. 
19646  Mains  scheideckeri                           19669  Mains  mains  var. 
19664  Mains  toringo  19688  Mains  pendula 

Represented  by  top-grafts  only 

19631  Mains  sylvestris  19670  Mains  astrachanica 
19643  Mains  siberica  frutico                       19683  Mains  niedwietzkyana 

coccinea 
Represented  by  top  and  root-grafts 

19651  Mains  arnoldiana  19662  Mains  ringo 

19689  Mains  ringo  sublobata 

Less  than  25  percent  of  the  forms  were  successfully  perpetuated ;  this 
is  a  very  low  percentage,  but  really  higher  than  was  expected  judging 
from  the  condition  of  the  scion  material  when  received. 

Scions  from  Arnold  Arboretum 

The  fifteen  kinds  surviving  served  as  an  acceptable  beginning  to 
the  collection  of  forms  of  Malus,  but  in  view  of  the  very  great  number 
of  published  species  and  varieties  included  in  the  genus,  could  be 
regarded  only  as  a  beginning ;  more  forms  were  desired.  Therefore,  in 
the  fall  of  1907,  an  appeal  was  made  direct  to  Dr.  C.  S.  Sargent  of  the 
Arnold  Arboretum.  In  response  to  this  appeal  a  package  of  scions  was 
received  on  January  9,  1908,  representing  fifty-seven  different  species 
and  varieties  of  the  genus.  The  scions  were  cut,  shipped  immediately, 
and  when  received  were  in  excellent  condition ;  they  were  labelled  with 
name  only;  thus  the  first  procedure  was  to  provide  serial  numbers. 
This  course  is  followed  with  most  plants  in  experiment  station  planta- 
tions because  of  simplicity,  economy,  and  decreased  liability  to  error. 
Where  several  kinds  of  plants  are  used,  each  handled  in  considerable 
numbers,  the  task  of  secure  labelling  is  a  serious  one,  and  abbreviation 
within  the  limits  of  certain  recognition  deserves  most  careful  attention. 
If  a  number  of  three  or  four  digits  can  take  the  place  of  a  binomial  of 
twelve  to  eighteen  letters,  or  a  trinomial  of  twenty  to  thirty  letters,  the 
saving  in  the  making  of  labels,  in  note-taking,  and  in  some  of  the 
records  is  a  large  item. 

Keys  to  names  are,  of  course,  necessary  and  at  first  are  freely 
used,  but  in  a  short  time  the  numbers  and  names  become  so  well 


1926] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


373 


associated  in  the  mind  of  the  worker  that  the  briefer  designation 
serves  all  purposes  of  references.  In  the  present  instance  the  scions 
were  arranged  alphabetically  by  name  and  then  given  numbers  serially 
from  801  to  857.  This  soon  became  known,  in  any  reference  to  these 
plants,  as  the  "800  series,"  just  as  surviving  plants  of  the  lot  received 
the  preceding  year,  in  which  case  the  accession  numbers  as  applied  by 
the  Department  of  Agriculture  were  retained,  became  known  as  the 
"19000  series."  Neither  series  conflicts  with  other  series  of  numbers  in 
use,  and  in  the  800  series  the  first  digit  serves  as  a  perpetual  reminder 
of  the  year  in  which  the  series  was  instituted.  The  list  of  scions 
received  with  the  prefixed  numbers  as  in  the  key  in  common  use  is  as 
follows: 


801  Mains  angustifolia 

802  Mains  arnoldiana 

803  Mains  astrachanica 

804  Mains  atrosanguinea 

805  Mains  baccata  aurantiaca 

806  Mains  baccata,  red  fruit  443-1 

807  Mains  baccata,  bright  red 

fruit,  late 

808  Mains  baccata  var. 

809  Mains  baccata  var. 

810  Mains  baccata  maxima 

811  Mains  baccata  oblonga 

812  Mains  baccata  X  prunifolia 

813  Mains  baccata  sanguinea 

814  Mains  baccata  var.  sieboldi 

815  Mains  baccata  X  toringo 

816  Mains  cashmere 

817  Mains  crataegifolia 

818  Mains  coronaria 

819  Mains  dioica 

820  Mains  fastigiata  bifera 

821  Mains  floribunda 

822  Mains  Fluke  apple 

823  Mains  halliana 

824  Mains  Hyslop  Crab 

825  Mains  ioensis 

826  Mains  ioensis  fl.  pi. 

827  Mains  kaido 

828  Mains  prunifolia  macrocarpa 

829  Mains  mains  441-1 


830  Mains  mains 

831  Mains  mains  X  baccata 

832  Mains  pendula 

833  Mains  mains  fl.  pi. 

834  Mains  niedwietzkyana 

835  Mains  prunifolia 

836  Mains  prunifolia  flava 

837  Mains  prunifolia  macrocarpa 

838  Mains  prunifolia  (fine  var.) 

839  Mains  prunifolia  xanthocarpa 

840  Mains  ringo 

841  Mains  rivularis 

842  Mains  rivularis  var. 

843  Mains  sargenti 

844  Mains  scheideckeri 

845  Mains  sikkimensis 

846  Mains  soulardi 

847  Mains  spectabilis 

848  Mains  spectabilis  615 

849  Mains  spectabilis  var.  459-4 

850  Mains  sylvestris 

851  Mains  toringo,  yellow  fruit 

852  Mains  toringo,  dwarf,  spreading 

form 

853  Mains  toringo,  red  fruit 

854  Mains  ringo  sublobata 

855  Mains  zumi 

85QMalussp.  (?)  5004,  yellow  fruit 
857  Mains  Yellow  Siberian  Crab 


Root-grafting  on  apple  seedling  stocks  was  begun  January  11  and 
was  finished  January  20.  The  total  number  of  grafts  made  was  570, 
an  average  of  10  for  each  number.  This  did  not  utilize  all  of  the  scion 
wood  except  for  four  numbers.  In  the  period  April  4  to  9  the  remain- 
ing scions  of  53  of  the  kinds  were  top-worked  on  young  trees  in  Plat  I. 
The  grafts  ranged  from  2  to  15  for  each  species  or  variety,  a  total 
of  396.  Twenty-three  of  the  kinds  were  worked  on  Sops  of  Wine;  14 
on  Fameuse,  and  18  on  Virginia  Crab  seedlings. 


374  BULLETIN  No.  275  [June, 

In  the  fall  of  1908  the  number  of  root-grafts  living  was  144,  repre- 
senting 39  of  the  kinds  grafted,  and  of  the  top-grafts,  176,  representing 
38  kinds,  were  alive. 

Scions  of  nine  of  the  series  failed  to  grow  either  as  root-grafts  or 
top-grafts;  these  were: 

805  Mains  baccata  aurantiaca  828  Mains  prunifolia  macrocarpa 

812  Mains  baccata  X  prunifolia  835  Mains  prunifolia 

815  Mains  baccata  X  toringo  844  Mains  scheideckeri 

816  Mains  cashmere  847  Mains  spectabilis 
827  Mains  kaido 

One,  No.  845  Mains  sikkimensis,  root-grafted  only,  failed  to  grow. 
Thus  10  of  the  57  numbers  were  lost,  leaving  47  with  living  representa- 
tives at  the  end  of  the  first  season.  Ten  of  these  appear  only  in  the 
list  of  root-grafts,  8  only  in  the  list  of  top-grafts,  and  29  have  repre- 
sentation in  both  lists. 

Six  kinds  under  numbers  of  the  800  series  had  duplicates  in  the 
19000  series;  these  were: 

832  Mains  pendula same  as  19688 

840  Mains  ringo same  as  19662 

843  Mains  sargenti same  as  19630 

846  Mains  soulardi same  as  19665 

852  Mains  toringo same  as  19664 

854  Mains  ringo  sublobata same  as  19689 

There  are  then  five  of  the  19000  series  to  be  added  to  the  47  kinds 
represented  in  the  800  series  to  make  up  the  total  of  forms  of  Malus 
represented  in  the  collection.  These  are  M.  mains  444/1  (19669), 
represented  by  two  trees  now  fifteen  years  old  from  root-grafts. 
Neither  of  these  trees  has  flowered  as  yet.  M.  mains  var.  (19667),  a 
form  that  has  flowered  regularly  and  abundantly  since  1913,  the  sev- 
enth year  from  graft,  is  a  crab-like  form  quite  distinct  from  any  other 
form  in  the  collection.  M.  arnoldiana  (19651)  is  erroneously  named. 
M.  arnoldiana  as  802  closely  resembles  M.  floribunda,  of  which  it  is 
said  to  be  a  seedling,  but  19651  is  totally  different  in  habit  of  growth, 
foliage,  flower,  and  fruit.  It  is  plainly  a  form  of  M .  prunifolia,  and  in 
the  list  of  descriptions  it  is  placed  as  M.  prunifolia  var.  (33),  M. 
scheideckeri  (19646),  and  M.  microcarpa  (19644). 

To  replace  some  of  the  kinds  that  failed  in  1908  a  further  lot  of 
scions  representing  eleven  of  the  numbered  forms  was  received  from 
the  Arnold  Arboretum  in  the  spring  of  1912.  These  were  numbered 
1201  to  1211  and  constitute  what  is  referred  to  as  the  1200  series. 
Three  of  these,  namely,  M.  baccata  var.  (1202),  the  equivalent  of  809, 
M.  baccata  aurantiaca  (1203),  the  equivalent  of  805,  and  M.  specta- 
bilis var.  459-4  (1211),  the  equivalent  of  849,  failed  again;  the  remain- 
ing eight  of  the  series  are  represented  by  2  to  10  root-grafted  trees  now 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  375 

twelve  years  old.  Eliminating  duplications  there  are  now  51  kinds  in 
the  collections.  This  is  more  than  enough  for  any  breeding  that  is 
likely  to  be  attempted,  but  falls  far  short  of  representing  all  the  forms 
of  the  genus  that  have  been  dignified  by  specific  or  varietal  names. 


376  BULLETIN  No.  275  [June, 

HYBRIDIZING:    DIVISION  INTO  CLASSES 
AND  GROUPS 

What  follows  was  written  in  1917  and  is  an  account  of  hybridizing 
done  up  to  that  time.  Hybrid  seedlings  of  known  parentage  from 
crosses  made  in  the  earlier  years  began  fruiting  in  1917,  and  nearly  all 
crosses  made  in  that  and  following  years  included  as  one  or  the  other 
or  both  of  the  parents  these  hybrid  seedlings.  It  is  not  the  purpose 
of  this  paper  to  consider  the  work  done  with  combinations  involving 
these  hybrid  seedlings. 

Hybridizing  apples  as  practiced  at  this  Station  has  involved  two 
quite  distinct  classes  of  plants;  namely,  (1)  orchard  varieties  and  (2) 
crabs  and  crab-like  forms  of  the  genus  Malus.  Because  of  the  differ- 
ences between  these  plant  classes,  the  combinations  that  have  been 
attempted  are  classified  for  convenience  into  four  groups  as  follows: 

1.  Orchard  varieties  X  orchard  varieties 

2.  Orchard  varieties  X  crab-like  forms 

3.  Crab-like  forms  X  orchard  varieties 

4.  Crab-like  forms  X  crab-like  forms 

Groups  1  and  4  are  combinations  within  the  respective  classes, 
while  Groups  2  and  3  are  combinations  of  the  two  classes.  Group  3  is 
the  reciprocal  of  Group  2  and  for  any  particular  pair  combined  in  the 
two  directions  the  gametic  composition  is  the  same  and  the  progeny 
is  expected  to  be  similar.  However,  a  marked  difference  in  the  degree 
of  success  attained  in  crossing  in  the  two  directions  has  been  encoun- 
tered in  practice.  Pollen  of  orchard  varieties  appears  more  acceptable 
to  stigmas  of  crab-like  forms  of  Malus  than  is  pollen  of  crab-like 
forms  to  stigmas  of  orchard  varieties.  This  fact,  which  developed 
early  in  the  work,  has  led  to  the  pollination  of  many  more  flowers  of 
crab-like  forms  than  of  orchard  varieties.  It  should  not  be  under- 
stood, however,  that  all  or  even  a  very  large  proportion  of  attempts  to 
hybridize  orchard  varieties  by  pollen  from  crab-like  forms  fail;  some 
such  combinations  have  been  highly  successful,  but  considering  the 
aggregate  of  attempts  in  the  two  directions  the  results  warrant  the 
statement  as  made.  The  ratios  of  fruits  to  flowers  were,  for  crab-like 
forms  X  orchard  varieties,  1  to  4.41,  and  for  orchard  varieties  X  crab- 
like  forms,  1  to  6.29.  No  structural  differences  have  been  discovered 
that  can  in  any  way  account  for  the  frequent  difference  in  behavior  of 
pollinations  in  the  two  directions,  but  the  fact  is  well  established  that 
it  is  easier  to  hybridize  crab-like  forms  successfully  by  pollen  of 
orchard  varieties  than  it  is  to  produce  fruits  by  the  reverse  process. 

Nearly  three  times  as  many  combinations  have  been  made  in 
Group  1  as  in  Group  4,  and  the  number  of  flowers  of  orchard  varieties 
pollinated  in  Group  1  is  seven  times  greater  than  the  number  of  flowers 
of  crab-like  forms  pollinated  in  the  combinations  of  Group  4.  This  is 
partly  because  orchard  varieties  have  been  available  since  the  work 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  377 

began,  while  considerable  numbers  of  the  crab-like  forms  have  become 
available  only  during  the  later  years,  and  partly  because  the  chief  effort 
has  been  directed  towards  combinations  of  orchard  varieties  and  to 
securing  hybrids  between  orchard  varieties  and  the  crab-like  forms. 
Combinations  of  crab-like  forms  have  been  neglected;  perhaps  as 
much  because  of  their  deficiency  in  economic  value  as  for  any  other 
reason,  altho  such  combinations  are  certainly  equal,  if  not  superior,  to 
combinations  of  orchard  varieties  for  studies  of  character  transmission. 
These  crab-like  forms  have  more  distinctly  marked  differentiating 
characters  than  have  the  orchard  varieties,  and  the  different  forms  of 
the  group  hybridize  even  more  readily  than  do  orchard  varieties. 

In  the  hybridizing  thus  far  done  there  have  been  used  43  orchard 
varieties  and  49  crabs  or  crab-like  forms  of  Malus.  The  numbers  of 
parental  combinations  in  the  several  years  range  from  28  in  1909  to 
235  in  1916.  The  aggregate  of  these  yearly  totals  is  744,  but  many  of 
the  combinations  have  been  attempted  in  more  than  one  year;  elimin- 
ating these  duplications  it  appears  that  the  aggregate  of  distinct  par- 
ental combinations  is  630  for  the  seven  years.  The  total  of  flowers 
pollinated  is  34,347,  the  number  of  fruits  having  viable  seeds  6,619,  a 
ratio  of  fruits  harvested  to  flowers  pollinated  of  1  to  5.19.  In  the 
account  to  be  given  of  the  hybridizing  attempted  during  the  seven 
years  thru  which  the  work  extended,  it  will  be  convenient  to  maintain 
the  division  into  the  four  groups  that  have  been  mentioned,  consider- 
ing the  first  group  No.  1. 

GROUP  1 :   ORCHARD  VARIETIES  X  ORCHARD  VARIETIES 

Hybrids  in  this  group  are  between  such  varieties  as  have  been 
available  in  the  Station  plantations.  The  combinations  made  have  all 
had  as  an  objective  the  testing  of  stability,  potency,  and  manner  of 
transmission  to  progeny  of  tangible  parental  characters.  In  most 
cases  choice  of  parents  has  been  based  upon  specific  characters  such  as 
size,  color,  flavor,  and  season  of  fruit,  character  of  foliage,  or  habit  of 
growth  of  tree.  Varieties  producing  large  fruits  have  been  paired  with 
varieties  producing  large  fruits  and  with  varieties  producing  small 
fruits.  Red  color  of  fruits  has  been  paired  with  red  color  and  with 
yellow;  yellow  with  yellow  and  with  red;  sour  with  sour  and  with 
sweet;  summer  with  summer,  with  fall,  and  with  winter.  In  many 
cases  the  crossing  has  been  reciprocal. 

There  appears  to  be  no  basis  other  than  visible  characters  upon 
which  to  rest  choice  of  parents.  Except  that  Ingram  is  said  to  be  a 
seedling  of  Rails,  and  Isham  a  seedling  of  Bailey  Sweet,  nothing  is 
known  of  the  immediate  parents  of  the  varieties  used,  and  as  to  the 
ancestry  of  parents  no  records  whatever  are  available.  Most  varieties 
are  discovered  or  resurrected.  When  one  interested  in  fruit  and  on 
the  watch  for  new  things  visits  or  chances  to  pass  a  long  neglected 


378  BULLETIN  No.  275  [June, 

farm  orchard  near  the  time  of  fruit  maturity,  he  notes  an  individual 
tree  the  fruits  of  which  are  attractive.  He  takes  scions,  propagates 
them,  brings  trees  to  fruiting,  attaches  a  varietal  name,  advertises  and 
disseminates  it  as  a  new  variety.  Probably  the  tree  thus  discovered 
was  planted  from  three  to  five  decades  previously;  it  may  have  been 
imported  from  a  distant  state  and  planted  as  a  named  variety  selected 
because  of  its  known  or  reputed  good  qualities.  No  record  is  kept. 
The  owner  who  did  the  planting  gives  attention  to  his  trees  and  takes 
pride  in  them  for  some  years,  then  dies,  migrates,  or  sells  the  property ; 
neglect  follows  and  most  trees  die;  the  survivors  pass  from  one  owner 
to  another  until  the  time  of  rediscovery  and  resurrection.  To  how 
many  varieties  of  today  such  a  history  would  apply  is,  of  course, 
unknown,  but  it  seems  at  least  probable  than  many  of  the  new  intro- 
ductions of  the  last  fifty  years  may  have  had  similar  histories. 

Some  varieties  are  assigned  to  origin  as  "chance  seedlings."  These 
are  discovered  in  the  same  manner  as  the  varieties  referred  to  as 
having  been  resurrected,  and  for  all  that  is  definitely  known  may 
actually  belong  to  the  same  class,  for  to  say  of  a  mature  fruiting  tree 
growing  in  a  fence  corner  or  in  some  out  of  the  way  place  that  it  is  a 
chance  seedling  is  merely  an  assumption  in  the  absence  of  any  histor- 
ical facts.  Division  fences  are  sometimes  changed  and  it  does  not  take 
long  to  develop  an  appearance  of  long  neglect  in  a  fence  row;  so  too,  a 
fine  orchard  may  in  a  few  years  become  a  typical  "waste  place."  Few 
of  our  varieties  have  definite  histories  and  not  one  has  a  known 
pedigree. 

Origin  of  Cultivated  Varieties 

All  orchard  varieties  are  classed  under  the  one  species  Pirus 
mains,  as  established  by  Linnaeus  in  the  first  edition  of  his  "Species 
Plantarum"  of  1753.  Presumably  Linnaeus  based  the  species  upon  some 
form  or  forms  of  the  wild  apple  commonly  found  in  most  parts  of 
Europe.  When  the  genus  Malus,  which  was  first  established  by  Tour- 
nefort1  in  1700,  but  by  succeeding  botanists,  including  Linnaeus,  rele- 
gated to  a  section  under  the  genus  Pyrus,  was  resurrected  a  few  years 
since,  the  common  apple  became  Malus  mains,  and  that  is  now  the 
commonly  accepted  name.  Present  day  varieties  have  come  down  to 
us  thru  centuries  of  cultivation.  The  beginning  of  domestication  of 
the  apple  is  unknown ;  even  the  most  ancient  writers  who  mention  the 
apple  treat  it  as  a  cultivated  fruit.  De  Candolle2  included  the  apple 
among  those  plants  cultivated  for  more  than  four  thousand  years  and 
says,  "I  consider  the  apple  to  have  existed  in  Europe,  both  wild  and 
cultivated,  from  prehistoric  times." 

Professor  Karl  Koch,  from  studies  based  upon  observations  and 
plant  material  collected  during  extended  travel  in  the  eastern  parts  of 

'Tournefort,  J.  P.    Inst,  Rei  Herb.    1700. 

2Koch,  Karl.    Origin  of  Cultivated  Plants,  Eng.  ed.,  236.    1886. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  379 

the  Caucasus,  Mongolia,  Tartary,  and  certain  Chinese  provinces, 
arrives  at  the  conclusion  that  the  apple  was  not  originally  wild  in 
Europe.  He  says,1 

"So  much  seems  to  me  certain,  neither  the  apple  found  here  in  Europe, 
called  wild  apple,  nor  the  pear-like  races  are  to  be  regarded  as  species.  We  have 
looked  at  them  only  as  wild  plants.  Neither  the  apple  nor  the  pear  were  origi- 
nally wild  in  Europe.  This  assertion  is  confirmed  by  this,  that  the  many  wild 
apples  and  pears  themselves  do  not,  as  a  rule,  resemble  each  other." 

Professor  Koch  recognizes  the  difficulty  of  ascertaining  with  cer- 
tainty the  species  from  which  the  cultivated  apple  has  descended  and 
raises  the  long  period  of  cultivation  as  the  obstacle  which  effectually 
bars  the  way  to  knowledge  of  the  original  species.  He  cites  the  evi- 
dence of  long  cultivation  and  expresses  the  belief  that  the  European 
forms  now  regarded  as  wild  are  probably  hybrids  escaped  from  cultiva- 
tion. When  the  long  period  of  cultivation  is  considered  it  does  not 
seem  strange  that  variation  should  have  occurred,  or  that  the  number 
of  forms  should  have  become  as  great  and  as  diverse  as  they  are  now 
known  to  be.  To  quote  further  from  Professor  Koch,2 

"It  appears  to  me  that  four  or  perhaps  five  species  formed  the  foundation 
for  our  apples.  It  is  possible,  and  to  me  seems  probable,  that  these  four  species 
are  so-called  Darwinian  species,  that  is  to  say,  in  the  dissemination  thru  the 
long  period  of  development  the  first  formed  constantly  deviated  and  the  species 
thus  formed  have  by  long  propagation  by  seeds  similarly  continued  to  form 
others.  These  four  or  five  ancestors  are  Pyrus  (Mains)  pumila  Mill.,  dasyphylla 
Borkh.,  sylvestris  Mill.,  and  prunifolia  Willd.  Perhaps  also  Pyrus  spectabilis 
should  be  included  with  our  cultivated  apples." 

Of  the  forms  named  by  Koch  the  first,  Pyrus  pumila,  is  the  most 
common  and  has  the  widest  distribution.  Probably  this  was  one  of 
the  forms  and  possibly  the  second,  dasyphylla,  was  another  upon 
which  Linnaeus  based  his  species  Pirus  malus.  The  following  charac- 
terization of  the  different  species  is  condensed  from  Koch's  "Dendrol- 
ogie."3 

Pyrus  (Malus)  pumila  is  usually  shrubby  but  sometimes  becomes  arbor- 
escent; leaves  elliptical,  tomentose  beneath,  styles  glabrous  not  longer  than  the 
stamens;  fruit  umbilicate  at  base,  pedicel  short,  stout.  Commonly  seen  in 
thickets  and  most  abundant  in  southeast  Russia,  Caucasus,  Tartary,  and  the  Altai 
Mountains.  It  grows  as  vigorously  as  Malus  sylvestris  but  always  remains  low 
and  is  not  long-lived;  it  is  used  as  a  stock  for  dwarfing  standard  orchard 
varieties.  Under  the  name  Malus  tartarica  the  plant  is  common  in  gardens  under 
several  forms,  as  (1)  The  Johannis  apple,  distinguished  by  scant  pubescence  which 
is  entirely  confined  to  the  top  shoots  of  the  current  year  and  to  the  lower  side  of 
the  young  leaves,  and  by  shining  brown  bark  and  brittle  roots.  The  leaves  taper  in 
both  directions  and  are  longer  than  in  other  forms;  the  fruit  is  oblong,  yellow, 
and  is  borne  in  clusters,  ripening  early  in  July.  (2)  The  Splitt  or  Sweet  apple,  which 
has  felt-like  tomentum  on  young  shoots  and  on  the  lower  side  of  the  shorter 


'Koch,  Karl.    Dendrol.  1,  202.    1869. 
2loc.  cit.,  202. 
3loc.  cit.,  203-210. 


380  BULLETIN  No.  275  [June, 

leaves.  This  form  is  less  wide-spreading  and  commonly  forms  a  single  trunk  the 
bark  of  which  is  Indian  red.  The  fruits  are  oblate  and  ripen  later  than  those 
of  the  Johannis  apple.  The  Splitt  apple  is  the  Doucin  or  Pomme  de  St.  Jean 
of  the  French,  the  Doucin  of  Holland,  the  common  Codlin  of  England.  (3)  The 
Corn  or  Jacob's  Apple,  very  similar  to  the  preceding,  but  less  pubescent.  Its 
fruits  are  globular,  straw-colored,  scentless,  and  subacid.  (4)  The  Heck  Apple 
(Mains  frutescens  Borkh.  Handb.  d.  Forstbot.  2,  1267) .  This  has  wholly  glabrous 
leaves  and  bushy  form,  is  probably  closely  allied  with  Mains  sylvestris  and  is 
possibly  a  hybrid  between  that  species  and  a  form  of  pumila.  (5)  The  fig-apple 
(Pyrus  dioica  Mnch  Verz.  ansl.  Baume  87,  t.  5,  P.  apetala  Miinchh.  Hausv.  5,  247) 
which  has  neither  petals  nor  stamens  and  produces  a  fruit  without  kernels. 

The  second  species  enumerated  as  one  of  the  probable  ancestors  of  the 
common  apple  is  Pyrus  (Mains)  dasyphylla  Borkh.  Handb.  d.  Forstbot.  2,  1269 
(1803).  This,  probably,  is  wild  only  in  the  orient.  It  is  arborescent  and  the  fruit 
ripens  in  September  and  October.  Leaves  broadly  elliptical,  variable  in  size,  but 
usually  2  to  2^/2  inches  wide  and  3  to  4  inches  long,  tomentose  beneath,  styles 
longer  than  the  stamens,  hairy  about  the  base;  fruit  umbilicate  at  base,  stem 
short,  stout,  except  that  the  common  form  is  arborescent  with  less  thorny  and 
more  horizontal  branches.  It  closely  resembles  Mains  pumila.  It  is  possible  that 
this  species  was  developed  thru  long  cultivation  and  then  became  wild.  Some  of 
the  forms  are  said  to  have  lobed  leaves. 

The  third  species  is  Pyrus  (Malus)  sylvestris  Mill.  gard.  diet.  1  (1759)  7th 
ed.  This  is  known  as  the  smooth-leaved  apple  tree  and  probably  came  origi- 
nally from  southern  Siberia  and  northern  China.  It  is  abundant  in  the  wild 
state  in  Europe.  Under  cultivation  it  gives  rise  to  numerous  forms,  some  of 
which  closely  resemble  Malus  pumila  while  others  more  nearly  resemble  Malus 
prunijolia.  The  leaves  are  roundish,  often  cordate  at  base,  sparsely  pubescent 
above  when  young,  glabrous  below.  Claw  of  the  rose-colored  petals  very  short; 
styles  glabrous,  not  longer  than  the  stamens;  fruit  umbilicate  at  base,  stem 
short.  It  is  possible  that  this  species  is  only  a  wild  form  of  the  smooth-fruited 
summer  apple  which  originally  came  thru  cultivation  from  Malus  prunijolia. 

The  fifth  species  is  Pyrus  (Malus)  prunijolia  Willd.  phytogr.  I.  8.  (1794). 
The  plum-leaved  apple  tree  from  northern  China,  Tartary,  and  southern  Siberia. 
Arboreous;  leaves  long,  lanceolate  or  elliptical,  pubescent  beneath  only  when 
young,  petals  white,  styles  hairy  at  base,  fruit  umbilicate  at  base,  stem  long, 
slender.  There  are  numerous  forms  of  this  species.  In  some  the  fruits  are  quite 
small,  in  others  more  than  an  inch  in  diameter,  while  some  forms  bear  fruits 
large  enough  and  pleasant  enough  to  give  them  rank  as  orchard  varieties.  In 
color  the  fruits  are  yellow,  red,  or  striped;  some  light  yellow  fruits  have  a  trans- 
parent appearance.  The  ice-apple  of  Russia,  and  the  so-called  Astrachan  apple 
of  Europe,  which  is  also  transparent,  belong  here.  Most  forms  of  Malus  pruni- 
jolia have  subacid  fruits,  but  there  are  garden  varieties  that  are  sweet. 

The  fifth  species  which  Professor  Koch  somewhat  doubtfully 
included  among  the  possible  ancestors  of  the  common  apple  is  Pyrus 
(Malus)  spectabilis,1  a  native  of  China. 

"Leaves  long-lanceolate,  or  elliptical,  pubescent  below  when  young;  claw 
of  the  rose-red  petals  longer  than  the  short  calyx  lobes,  styles  woolly  at  base, 
fruit  scarcely  umbilicate,  imperfectly  10-celled.  Malus  spectabilis  is  closely 
related  to  Malus  prunijolia,  but  is  distinguished  by  the  longer  narrower  leaves 
which  are  dull  in  color  and  more  tardily  glabrate  beneath,  the  flowers  also  are 
larger  and  rose-red  while  those  of  Malus  prunijolia  are  white." 


'Aiton,  William.    Hort.  Kew.,  ed.  1,  2,  175.    17S9. 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  381 

During  the  nineteenth  century  no  species  of  Malus  was  so  fre- 
quently mentioned  or  so  highly  praised  by  writers  treating  of  orna- 
mental trees  as  Malus  spectabilis.  It  was  widely  disseminated  and 
highly  prized  chiefly  for  the  brilliant  color  of  its  unopened  flower  buds. 
Professor  Koch  states  that  it  often  is  shrub-like,  but  commonly 
appears  as  a  tree  and  sometimes  attains  considerable  size.  Loudon1 
cites  several  trees  in  England  and  France  that  grew  to  large  size.  "In 
the  environs  of  London,  at  Spring  Grove,  a  tree  believed  to  be  upwards 
of  50  years  old,  was,  in  1834,  35  feet  high;  at  Kenwood,  38  years 
planted,  it  is  34  feet  high,  the  diameter  of  the  trunk  one  foot  seven 
inches,  and  of  the  head  28  feet."  Several  others  mentioned  range  from 
14  to  35  feet  in  height.  There  are  various  forms  of  this  species  some 
of  which  are  named  as  varieties  and  are  even  given  specific  rank  by 
some  writers;  such  as  Malus  sieboldi,  Malus  ringo,  Malus  kaido, 
Malus  riversi,  and  possibly  also  Malus  floribunda.  Some  forms 
accredited  to  Malus  spectabilis  have  leaves  in  some  degree  lobed  and 
calyx  lobes  wholly  or  in  part  deciduous,  thus  more  closely  resembling 
either  the  Japanese  species  toringo  or  the  Siberian  species  baccata. 
It  seems  most  probable  that  these  forms  are  hybrids  between  some 
form  of  Malus  spectabilis  and  either  Malus  toringo  or  Malus  baccata 
or  both. 

Professor  Koch's  extended  researches  into  the  origin  of  the  numer- 
ous forms  of  Malus  bring  out  clearly  the  hopelessness  of  the  attempt  to 
assign  definite  origin  to  the  widely  variant  forms,  because  of  the  long 
period  of  cultivation  and  the  undoubted  free  intermingling  of  original 
true  species. 

Varieties  Used  as  Parents  for  Hybrids  of  Group  1 

The  35  varieties  used  in  Group  1  were: 

Beach  (Apple  of  Fanny  Melonen  Tolman 

Commerce)  Grimes  Oldenburg  Twenty  Ounce 

Ben  Davis  Hall's  No.  6  Oliver  (Senator)  Willow 

Black  Ben  Davis  Huntsman  Osimoe  Winesap 

Borsdorf  Ingram  Rome  Winter  Rambo 

Collins  Isham  Shackleford  Wythe 

Delicious  Jefferis  Shockley  Yellow  Transparent 

Domine  Jonathan  Springdale 

Early  Ripe  Longfield  Summer  Pound 

Fameuse  Arkansas  Royal 

Place  of  origin  is  assigned,  altho  in  some  cases  doubtfully,  for  29 
of  these  varieties,  while  6  are  recorded  as  of  unknown  origin.  Six  are 
Russian,  6  came  from  Arkansas,  3  from  Pennsylvania,  3  from  Mis- 
souri, and  the  remaining  11  from  eleven  states  ranging  from  Rhode 
Island  on  the  east  to  Iowa  on  the  west.  Six  are  summer  varieties,  5 
are  fall  varieties,  and  24  are  either  early  or  late  winter  varieties.  Only 


'Loudon,  J.  C.    Arboretum  et  Fruticetum  Britannicum  2,  909.    1838. 


382  BULLETIN  No.  275  [June, 

two  varieties,  Isham  and  Tolman,  are  distinctly  sweet,  while  all  others 
are  of  varying  degrees  of  acidity. 

The  sum  of  the  matings  for  the  different  years  was  159,  but  10  of 
these  appeared  in  more  than  one  year  so  that  the  number  of  distinct 
combinations  was  149 ;  of  these  55  failed  entirely,  leaving  94  combin- 
ations represented  by  greater  or  less  numbers  of  successful  pollinations. 

The  total  number  of  flowers  pollinated  was  7,670,  and  of  these 
2,845  belonged  to  those  combinations  that  failed  entirely,  which  left 
4,825  as  the  number  of  pollinations  distributed  among  the  94  combin- 
ations that  were  in  some  degree  successful.  The  aggregate  of  fruits 
harvested  and  described  was  990. 

Percentages  of  successful  pollinations  ranged  from  2  percent  for 
each  of  five  combinations,  in  which  1  fruit  was  obtained  for  each  50 
flowers  pollinated,  to  77.25  percent  for  a  combination  yielding  34  fruits 
from  44  flowers  pollinated.  The  ratio  of  fruits  to  flowers  pollinated 
was  for  all  flowers,  1  to  7.7,  or  if  only  the  combinations  yielding  fruits 
are  considered,  1  to  4.87.  For  most  combinations  the  percentages  are 
low,  more  than  a  third  of  them  have  success  percentages  at  or  below 
10  percent;  49  combinations  have  success  percentages  ranging  between 
10  percent  and  50  percent,  and  for  11  combinations  the  percentages  are 
above  50.  The  maximum  referred  to  above  is  a  combination  of  Rome 
X  Collins  with  34  fruits  from  44  flowers  pollinated,  or  77.25  percent. 

It  is  scarcely  possible  to  point  out  specific  causes  accountable  for 
the  large  proportion  of  combinations  that  failed  entirely,  or  for  the 
extremely  low  percentages  of  success  that  prevailed  with  many  of  the 
matings.  Pollinations  were  made  in  the  orchard  and  equal  care  was 
exercised  in  all.  Of  the  several  causes  that  operate  to  limit  the  num- 
bers of  flowers  that  develop  fruits  when  undisturbed  except  by  natural 
agencies,  probably  all  were  operative  in  one  or  more  of  the  seasons 
except  that  of  failure  of  pollen  to  reach  stigmas.  In  all  of  the 
attempted  combinations  pollen  was  artificially  applied  to  the  stigmas 
of  each  flower,  so  that  if  failure  followed  it  must  be  ascribed  to  some 
cause  or  causes  other  than  the  failure  of  pollen  to  reach  the  stigmas. 
Pollen  may  be  defective,  or  of  low  vitality,  or  defect  may  rest  with  the 
stigmas,  or  some  constitutional  characteristic  of  either  parent  may 
inhibit  fertilization,  or  still  other  causes  may  be  active  in  determining 
results,  but  as  in  nature  four-fifths  of  the  flowers  fail  to  form  fruits  it 
is  reasonable  to  expect  a  considerable  proportion  of  failures  in  flowers 
artificially  pollinated. 

Perhaps  the  best  index  to  the  degree  of  success  attending  pollina- 
tion of  apple  flowers  on  trees  in  orchard  is  the  ratio  of  fruits  harvested 
to  flowers  pollinated.  This  ratio  for  the  aggregate  of  pollinations  in 
the  seven  years  1909  and  1911-1916  has  already  been  stated  to  be  1  to 
7.7,  but  there  were  very  wide  differences  in  seasons;  thus  the  ratio  for 
1914  is  1  to  3.88,  almost  exactly  double  the  ratio  for  the  aggregates. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  383 

At  the  other  extreme  for  attempted  matings  in  orchard  is  the  ratio 
1  to  92.25  in  1916.  This  extreme  needs  explanation;  it  is  based  upon 
8  combinations  involving  369  flowers  which  yielded  only  4  fruits.  Five 
of  the  8  combinations  included  223  flowers  and  failed  entirely.  The 
8  combinations  were  on  a  single  Jonathan  tree  as  the  pistillate 
parent.  The  flowers  emasculated  were  pollinated  by  pollen  from  8 
varieties;  50  flowers  by  Ben  Davis  gave  1  fruit;  49  flowers  by 
Fameuse  gave  1  fruit;  47  flowers  by  Longfield  gave  2  fruits.  These 
all  show  very  low  percentages  of  success.  The  other  varieties  used 
were  Shockley  on  47  flowers,  Collins  on  40  flowers,  Jefferis  on  48 
flowers,  Grimes  on  45  flowers,  and  Oldenburg  on  43  flowers;  none  of 
these  produced  fruits  and,  as  the  same  lots  of  pollen  used  on  other 
varieties  gave  a  reasonable  degree  of  success,  it  appears  that  the 
failures  in  five  combinations  and  the  near  failure  in  the  other  three 
must  be  ascribed  to  some  defect  in  the  pistil-bearing  parent  rather 
than  to  the  pollen  used.  Two  years  previously,  Jonathan  had  given  22 
percent  of  success  with  Grimes,  36  percent  with  Collins,  38  percent  with 
Domine,  and  8  percent  with  Arkansas;  hence,  the  failure  with  Grimes 
and  Collins  in  1916  indicates  a  seasonal  rather  than  a  constitutional 
defect. 

The  tree  bloomed  abundantly  and  with  one  exception  everything 
seemed  to  be  as  favorable  as  possible  for  success.  The  one  exception 
was  the  age  of  the  stigmas,  or  the  length  of  the  periods  between  emas- 
culation and  pollination.  These  periods  varied  from  three  days  and 
nine  hours  for  the  flowers  pollinated  by  Shockley  and  Collins  to  four 
days  and  eight  hours  for  those  pollinated  by  Oldenburg.  That  the 
periods  were  long  was  recognized,  but  cases  of  success  with  longer 
periods  were  matters  of  record  and,  as  accumulation  of  data  regarding 
behavior  of  stigmas  of  various  ages  were  desired,  pollination  was  per- 
formed. Had  the  stigmas  been  blackened  or  discolored  they  would 
have  been  discarded,  of  course,  but  they  were  not;  neither  did  they 
have  the  aspect  of  stigmas  in  ideal  condition,  their  appearance  indi- 
cating a  condition  near  enough  to  the  life  limit  to  raise  the  suspicion 
that  failure  would  follow  pollination.  The  doubt  as  to  possible  results 
could  only  be  cleared  by  actual  application  of  pollen;  there  seemed 
an  equal  chance  that  success  would  follow  and  that  chance  was  taken. 
How  near  the  life  limit  the  time  of  pollination  was,  is  seen  in  the  fact 
that  failure  was  not  absolute  in  all  matings;  five  failed  entirely,  but 
in  the  other  three  success  ranging  from  2  to  4.25  percent  was  recorded. 
Reviewing  all  the  circumstances  there  is  no  hesitancy  in  assigning  age 
of  stigmas  as  the  cause  of  the  low  ratio  of  fruits  to  flowers  in  these 
pollinations  on  Jonathan.  The  details  of  this  case  furnish  another 
example  of  the  objectionable  inclusion  of  a  special  problem  in  a 
general  scheme  of  breeding.  Determination  of  the  receptive  period 
of  stigmas  demands  the  extremes,  which,  in  fact,  are  the  essentials  of 


384  BULLETIN  No.  275  [June, 

the  problem,  and  are  reached  only  by  taking  chances  that  would  not 
and  should  not  be  taken  in  pursuing  a  definite  breeding  project  with 
apples  or  with  any  other  plant. 

Next  to  this  extreme  low  ratio  stands  a  ratio  of  1  to  13.11  derived 
from  the  pollination  of  2,151  flowers  in  1913,  which  matured  164 
fruits.  In  this  year  there  were  49  combinations,  26  of  which  failed 
entirely,  while  9  others  gave  success  percentages  below  5  percent.  In 
this  case,  however,  a  definite  trouble  was  accountable  for  the  failures, 
or  at  least  a  very  large  percentage  of  them,  altho  the  direct  cause  of 
the  difficulty  was  never  satisfactorily  determined.  Pollinations  in 
1913  were  made  under  favorable  conditions  and  there  was  every  reason 
to  expect  a  high  percentage  of  success,  but  on  removal  of  the  paper 
sacks,  about  four  weeks  after  pollination  of  the  flowers,  for  the  purpose 
of  substituting  cloth  sacks  on  those  clusters  carrying  fruits,  it  was 
discovered  that  flowers  and  leaves  within  many  of  the  sacks  were 
dying  or  were  already  dead  and  brown.  This  had  not  happened  in 
preceding  years,  nor  has  it  occurred  since.  Just  when  the  injury 
occurred  is  not  known,  but  from  the  fact  that  the  dead  leaves  and 
flowers,  altho  brown,  were  still  flexible  and  not  dry  and  crisp,  it  seems 
certain  that  injury  did  not  long  precede  examination.  There  was  no 
evidence  of  the  presence  of  insects  or  injurious  fungi.  Only  one  other 
possibility  was  suggested  and  that  was  that  alternation  of  showers  and 
sunshine  had  established  relations  between  wet  sacks  and  bright  sun- 
light, thru  which  interior  temperatures  were  raised  to  an  injurious 
degree.  Against  this  idea  was  the  fact  that,  in  a  number  of  instances 
sacks  containing  injured  twigs  were  in  close  proximity  to  others  in 
which  no  injury  occurred,  both  having  the  same  exposure.  In  all 
seasons,  in  the  interval  between  pollination  and  examination,  there 
have  been  periods  of  alternating  rain  and  sunshine,  but  only  in  this  one 
instance  did  injury  occur.  That  at  some  particular  time  there  existed 
a  combination  of  atmospheric  conditions  capable  of  inflicting  the 
injuries  observed  seems  a  possibility,  but  the  known  facts  are  in- 
sufficient basis  for  any  definite  conclusion. 

Other  ratios  of  fruits  to  flowers  pollinated  were,  for  1909,  1  to 
5.72;  for  1911,  1  to  7.8;  for  1912,  1  to  10.66;  and  for  1915,  1  to  4.88. 
The  rather  wide  range  of  ratios  apparently  was  due  to  seasonal  differ- 
ences, altho  in  no  year,  except  1913,  was  there  any  particular  circum- 
stance observed  that  could  be  referred  to  as  a  cause  of  observed  dif- 
ferences in  ratios.  In  a  number  of  instances  the  same  combination  was 
attempted  in  more  than  one  year,  giving  reasonable  success  in  one 
year  and  failing  entirely  the  next.  Violence  of  the  cross  can  scarcely 
be  appealed  to  as  responsible  for  any  of  the  failures  because  all  crosses 
in  this  group  are  between  varieties  that  presumably  belong  to  the  one 
species  Mains  mains;  they  are  groups  of  plants  that  differ  in  purely 
varietal  characters  and  the  relationship  is  not  distant. 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  385 

On  the  other  hand,  it  is  conceivable  and  does  not  seem  improbable 
that  failure  of  some  combinations  may  have  been  due  to  the  other 
extreme  of  relationship;  that  is,  so  nearly  related  as  to  exhibit  the 
self-sterility  which  has  been  demonstrated  to  be  an  attribute  of  most 
varieties  in  most  seasons.  The  particular  case  in  which  this  suspicion 
centers  is  the  reciprocal  combination  of  Domine  and  Winter  Rambo, 
already  referred  to  in  connection  with  seasonal  differences,  but  which 
may  be  considered  here  in  greater  detail.  These  varieties  are  very 
similar  in  appearance,  altho  Domine  has  the  longer  season  and  is  less 
highly  flavored;  both  have  the  habit  of  often  being  dull  in  color,  and 
often  the  fruits  of  the  two  varieties  are  scarcely  distinguishable. 

Domine  was  pollinated  by  Winter  Rambo  as  follows:  in  1909,  49 
flowers;  in  1911,  50  flowers;  in  1913,  60  flowers;  and  in  1915,  53 
flowers;  a  total  of  212  flowers,  all  of  which  failed  to  produce  fruits. 
Complete  failure  in  four  seasons  is  fairly  good  ground  for  the  belief 
that  these  two  varieties,  when  crossed  in  this  direction,  are  habitually 
sterile.  For  the  reciprocal,  Winter  Rambo. X  Domine,  pollinations 
were  as  follows;  in  1909,  62  flowers;  in  each  of  the  years  1911,  1913, 
and  1915,  47  flowers;  a  total  of  203  flowers.'  The  pollinations  of  1909, 
1911,  and  1915,  with  a  total  of  156  flowers,  failed  entirely,  giving 
almost  as  good  ground  for  the  suspicion  of  habitual  sterility  as  existed 
in  the  case  of  the  cross  Domine  X  Winter  Rambo,  but  suspicion  of 
habitual  sterility  in  crossing  Winter  Rambo  X  Domine  is  overthrown 
by  the  results  in  1913  when,  from  47  flowers  pollinated,  6  mature 
fruits  were  harvested.  This  is  only  12.75  percent  successful  for  that 
year  and  less  than  3  percent  for  the  aggregate  of  flowers  for  all  years, 
but  it  is  sufficient  to  show  that  suspicion  of  habitual  sterility  in  this 
cross  is  not  well-founded  and  that  under  some  conditions  a  certain 
degree  of  success  is  possible. 

In  what  manner  conditions  of  weather  or  of  the  trees  differed  in 
1913  from  the  other  years  in  which  entire  failure  resulted  is  unknown, 
but  that  there  was  a  difference  in  some  particular  seems  indicated  by 
the  different  results.  To  bear  out  the  idea  that  the  failures  here 
recorded  resulted  from  too  close  relationship  between  the  two  varieties, 
so  close  as  to  consider  them  strains  of  one  variety  and  that  the  crossing 
amounted  to  selfing,  the  fruits  produced  should  have  been  below 
normal  in  size,  deficient  in  seeds,  the  seeds  of  low  vitality  and  yielding 
only  weak  seedlings,  but  this  is  not  in  accordance  with  the  facts.  The 
6  fruits  were  normal  in  size,  ranged  high  in  seed  production,  the  seeds 
were  viable  and  gave  seedlings  as  vigorous  as  from  most  other  crosses. 
The  6  fruits  contained  69  plump  seeds,  or  11.5  to  each  apple,  an 
average  nearly  40  percent  greater  than  the  average  of  8.27  seeds  to 
the  apple  obtained  from  examination  of  12,912  apples  of  large  size 
representing  32  orchard  varieties.  Of  the  69  seeds,  63,  or  91.3  percent, 
germinated;  the  seedlings  planted  in  orchard  in  the  spring  of  1916 


386  BULLETIN  No.  275  [June, 

numbered  56  and  at  the  end  of  the  season,  in  November,  50  were 
living  and  were  rated  as  follows:  good  trees,  33;  fair  trees,  6;  poor 
trees,  11.  This  is  a  larger  proportion  of  good  trees  than  is  found  in 
most  other  similar  lots  of  hybrid  seedlings.  High  content  of  viable 
seeds  and  vigor  of  seedlings  is  decidedly  against  the  suggestion  that 
the  high  percentage  of  failure  in  this  cross  may  be  due  to  sterility 
arising  from  close  relationship  of  the  varieties  paired.  In  spite  of  the 
close  resemblance  of  the  fruits,  the  varieties  Winter  Rambo  and 
Domine  must  be  considered  as  distinct  varieties,  and  the  cause  of 
entire  failure  to  cross  in  one  direction  and  partial  failure  to  cross  in 
the  other  direction  may  not  properly  be  ascribed  to  close  relationship, 
but  must  rest  in  some  factor  or  factors  at  present  unknown. 

Of  the  varieties  mated,  Oldenburg  has  the  highest  ratio  between 
fruits  matured  and  flowers  pollinated;  584  flowers  pollinated  gave 
222  fruits,  or  a  ratio  of  1  to  2.63 ;  this  represents  10  combinations,  one 
of  which,  that  with  Winter  Rambo,  failed  entirely.  The  percentages 
of  success  for  the  other  9  combinations  ranged  from  6.12  percent  for 
Rome  to  76.5  percent  for  Hall's  No.  6.  Next  to  Oldenburg  in  accom- 
plishment stands  Rome,  with  a  record  of  554  pollinations  yielding  193 
fruits,  a  ratio  of  1  to  2.86.  There  were  12  combinations  represented 
with  percentages  of  success  ranging  from  8.1  percent  for  Isham  to 
77.25  percent  for  Collins.  Other  varieties  with  high  ratios  were 
Wythe,  1  to  3.4;  Longfield,  1  to  4.6;  Grimes,  1  to  5.6;  Shackleford, 
1  to  6.1;  and  Yellow  Transparent,  1  to  6.6.  The  varieties  mentioned 
are  those  having  the  best  records;  certain  other  varieties  took  places 
at  the  other  extreme,  either  with  records  of  entire  failure  or  with  very 
low  percentages  of  success;  thus  Arkansas  with  273  flowers  pollinated, 
in  numbers  from  32  to  96,  by  five  different  pollen  plants,  yielded  no 
fruits,  and  Winesap  with  247  pollinations  distributed  among  seven 
pollen  plants  also  failed  to  yield  fruits.  Low  percentages  of  success 
are  recorded  for  Beach,  1.13  percent;  Fanny,  2  percent;  Isham,  4.5 
percent;  and  Willow,  4.6  percent.  Remaining  varieties  of  the  list 
range  intermediate  between  those  mentioned  in  percentages  of  suc- 
cessful pollinations. 

Seed  Production  in  Hybrid  Fruits  in  Group  1 

Seed  production  of  the  hybrid  fruits  in  this  group  of  orchard 
varieties  X  orchard  varieties  is  rather  low.  The  990  fruits  produced 
6,989  seeds  that  were  saved  for  planting;  this  gives  an  average  of  7.05 
seeds  to  each  fruit.  A  fraction  above  11  percent  must  be  added  to 
this  average  to  equal  the  average  obtained  from  count  of  seeds  in 
21,412  apples  that  had  developed  from  flowers  pollinated  by  natural 
agencies,  which  is  7.85  seeds  to  each  apple.  The  apples  from  open 
pollinated  flowers  contained  seeds  in  numbers  ranging  from  0  to  27, 
while  the  fruits  from  flowers  artificially  pollinated  had  a  seed  range 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  387 

from  2  to  15.  Only  3  of  the  94  combinations  had  seed  averages  equal 
to  or  exceeding  the  full  complement  of  a  normal  apple,  namely,  10 
seeds.  Six  combinations  had  averages  of  9  or  above,  but  less  than  10; 
60  combinations  had  averages  of  6  or  above  but  less  than  9;  and  25 
had  averages  of  less  than  6.  The  three  combinations  having  averages 
above  10  are  Winter  Rambo  X  Domine — 6  fruits  from  pollination  of 
47  flowers  contained  69  seeds,  an  average  of  11.5;  Winter  Rambo 
X  Jonathan — 7  fruits  from  47  flowers  pollinated  contained  73 
seeds,  an  average  of  10.42;  and  Huntsman  X  Osimoe,  in  which  49 
flowers  pollinated  gave  5  fruits  containing  51  seeds,  an  average  of  10.2. 
The  minimum  seed  production  is  found  in  two  combinations,  Ben 
Davis  X  Twenty  Ounce,  in  which  pollination  of  50  flowers  gave  1 
fruit  yielding  2  seeds,  and  Jonathan  X  Fameuse,  in  which  49  flowers 
pollinated  gave  1  fruit,  also  containing  only  2  seeds. 

Table  2  gives  the  distribution  of  seeds  in  the  hybrid  fruits  of  the 
group  orchard  varieties  X  orchard  varieties.  It  will  be  observed 
that  the  aggregate  of  fruits  included  in  the  tabulation  was  977,  while 
the  aggregate  of  fruits  produced  in  the  group  was  990.  This  differ- 
ence of  13  represents  those  fruits  for  which  the  seed  record  was 
wanting  or  incomplete.  They  were  fruits  whose  seeds  had  been 
wholly  or  partially  destroyed  by  insects  and  for  this  reason  were 
omitted  from  the  tabulation  of  seed  distribution.  There  were  six 
different  matings  that  had  one  such  fruit  in  each,  two  matings  that 
had  two  each,  and  one  mating  of  Grimes  X  Shackleford  that  had 
three.  The  infestation  was  in  all  cases  by  second-brood  larvae  of  the 
codling  moth;  fruits  were  in  large  measure  protected  by  the  cheese- 
cloth sacks  with  which  they  were  covered,  but  infestation,  particularly 
where  two  fruits  develop  in  the  same  sack,  is  very  often  possible  and 
occasionally  occurs. 

Seeds  Planted  in  Group  1 

There  is,  in  many  cases,  some  difference  between  the  total  seeds 
saved  from  hybrid  fruits  and  the  number  planted.  The  season  of 
maturity  of  hybrid  fruits  has  extended,  in  the  several  years,  from 
July  22  for  Yellow  Transparent  to  November  11  for  Wythe  and 
Collins.  As  fruits  reach  maturity  they  are  picked,  described,  the 
seeds  extracted,  and  such  as  appear  sound  are  placed  in  envelops 
which  are  classified  and  stored  in  a  vault  where  they  remain  until 
time  for  planting.  In  the  earlier  years  of  the  work  it  was  the  custom 
to  stratify  the  seeds  in  sand  late  in  the  fall,  bury  the  receptacles  in  a 
pit  for  the  winter,  and  then  plant  in  the  spring.  This  plan  did  not 
prove  to  be  wholly  satisfactory.  Apple  seeds  germinate  at  very  low 
temperatures.  In  some  seasons,  warm  periods  in  late  February  or  early 
March  will  start  the  germinating  process  long  before  it  is  thought 
possible  to  plant  and  care  for  the  seeds.  In  1910,  and  again  in  1912, 


3S8 


BULLETIN  No.  275 


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1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  389 

this  early  activity  occurred.  Altho  the  conditions  were  carefully 
studied,  judgment  was  in  error  as  to  the  time  for  lifting  the  containers, 
germination  has  commenced,  and  some  losses  were  experienced  in 
removal  and  planting. 

For  the  past  three  seasons  planting  has  been  done  the  first  week 
in  December.  Dirt  bands  made  of  veneer  cut  to  fold  21/£  inches 
square  and  5  inches  deep  are  arranged  in  greenhouse  flats  of  proper 
dimensions  to  hold  eighty-four  bands;  these  are  filled  with  good 
garden  soil  and  a  single  seed  planted  in  each  band.  Record  of  plant- 
ing is  kept  on  sheets  ruled  in  squares  corresponding  to  the  bands  in 
each  numbered  flat.  When  planting  is  completed  the  flats  are  stacked 
in  a  pit  excavated  for  the  purpose.  This  pit  is  of  proper  dimensions 
to  hold  two  ranks,  four  flats  deep  and  long  enough  to  accommodate 
whatever  number  is  in  use.  Each  flat  is  accurately  placed  so  that  no 
cracks  are  left  that  would  allow  entrance  for  mice,  and  the  whole  is 
covered  with  sheet  metal  to  prevent  flooding  in  case  of  heavy  rains. 
When  the  stack  is  complete  it  is  covered  with  earth  which  is  rounded 
above  and  so  shaped  as  to  provide  perfect  drainage.  In  early  spring, 
usually  the  third  week  in  March,  the  flats  are  removed  to  cold  frames, 
arranged  in  numerical  order,  and  a  41/->-inch  pot  label  bearing  the 
proper  number  is  placed  in  each  band.  The  date  of  appearance  of 
each  seedling  is  recorded  on  forms  prepared  for  the  purpose.  In  May 
the  bands  containing  seedlings  are  placed,  1  foot  apart,  in  nursery 
rows. 

This  method  of  handling  several  thousand  seeds  and  preserving 
the  identity  of  each  has  proved  very  satisfactory.  Assuming  Decem- 
ber 6  as  the  date  of  beginning  planting  (this  was  the  actual  date  in 
1915  and  again  in  1916),  the  dry  storage  period  of  seeds  in  envelops 
may  vary  between  25  days  for  seeds  from  fruits  picked  on  the  latest 
picking  date  November  11  to  138  days  for  seeds  from  fruits  picked 
July  22.  During  this  period  of  storage  some  seeds  may  develop  defects 
that  were  not  apparent,  or  were  overlooked  at  time  of  extraction. 
Occasionally  a  seed  is  injured  in  cutting  the  fruit  at  the  time  seeds  are 
extracted,  or  a  seed  that  from  external  appearance  is  normal  and 
viable  may  have  an  embryo  so  defective  that  the  seed  shrivels  upon 
drying.  All  seeds  that  appeared  to  be  in  any  way  defective  were  dis- 
carded at  planting  time. 

Seed  Losses 

In  this  group  of  hybrids  (orchard  varieties  X  orchard  varieties) 
the  aggregate  of  seeds  saved  was  6,989.  The  number  planted  was 
6,440 — hence  549  represents  the  number  of  seeds  found  defective  and 
discarded  during  the  planting.  This  is  nearly  8  percent  of  the  aggre- 
gate of  seeds  saved.  In  51  of  the  94  matings  represented,  there  were 
no  losses,  the  number  planted  was  in  each  case  equal  to  the  number 
saved.  The  losses,  then,  were  distributed  among  43  matings  and 


390  BULLETIN  No.  275  [June, 

ranged  from  1  in  each  of  8  matings  to  109  in  the  cross  Shackleford 
X  Grimes;  in  this  case  a  loss  of  nearly  44  percent.  For  the  large 
majority  of  combinations  the  losses  of  seeds  between  extraction  and 
planting  are  very  small,  but  in  a  few  cases  they  are  large  enough 
to  attract  notice.  Examination  of  seeds  discarded  as  imperfect  indi- 
cates that  they  represent  a  stage  of  development  intermediate  between 
full  and  perfect  development  and  that  stage  frequently  observed  at 
the  time  of  extracting  seeds  from  fruits,  in  which  the  testa  appears 
fully  formed,  but  empty,  there  being  no  development  of  embryo. 

Percentages  of  Germination  Vary  Widely 

The  germination  considered  included  only  those  cases  where 
seedlings  appeared  at  the  ground  surface.  Doubtless  some  weak  seeds 
protruded  roots  or  even  started  development  of  the  caulicle,  but  did 
not  have  sufficient  vitality  to  reach  the  surface;  such  cases  were  not 
included  in  the  germination  record.  Of  the  6,440  seeds  planted,  4,007, 
or  62.22  percent,  were  recorded  as  having  germinated.  The  combina- 
tions were  between  parent  plants  that  are  quite  diverse  in  character, 
and  it  is  only  natural  that  there  should  be  wide  range  in  percentages 
of  germination.  The  minimum  percentage  was  3.13  in  the  cross 
Osimoe  X  Winter  Rambo;  of  32  seeds  planted  only  one  germinated. 
Next  above  this  was  the  cross  Yellow  Transparent  X  Oldenburg,  in 
which  14  fruits  gave  102  seeds,  of  which  number  only  7,  or  6.86  percent, 
germinated.  Other  combinations  showing  low  percentages  of  ger- 
mination were  Twenty  Ounce  X  Oldenburg,  in  which  2  of  15  seeds, 
or  12.5  percent,  germinated,  and  Yellow  Transparent  X  Domine,  in 
which  37  of  220  seeds  planted,  or  16.82  percent,  germinated.  At  the 
other  end  of  the  line  were  6  combinations  in  which  100  percent  ger- 
mination was  recorded,  but  these  involve  relatively  small  numbers 
of  seeds;  two  of  the  combinations  had  7  each,  2  had  8  each,  1  had  10, 
and  1  had  20.  Eight  combinations  had  percentages  of  germination 
between  90  and  100,  representing  480  seeds;  40  combinations  with 
2,495  seeds  had  percentages  of  germination  between  60  and  90;  per- 
centages for  the  remaining  combinations  ranged  down  to  about  20 
percent.  Compared  with  the  standards  of  germination  demanded  for 
seeds  of  cereals,  the  percentages  obtained  for  seeds  of  this  group  of 
apples  were  quite  low;  but  for  apple  seeds  representing  so  large  a 
variety  of  parental  combinations  and  developed  in  fruits  resulting 
from  artificial  pollinations,  the  general  average  of  62.22  percent  was 
perhaps  as  high  as  could  be  expected. 

Hybrid  Seedlings  Now  Living 

When  the  census  of  seedlings  resulting  from  the  pollinations  made 
in  the  group  under  consideration  was  taken  in  November,  1916,  there 
were  living  2,952  seedlings  1  to  7  years  of  age.  These  represent  45.98 


1926] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


391 


percent  of  the  aggregate  of  seeds  planted,  or  73.67  percent  of  the  seeds 
germinated.  To  state  the  results  in  a  different  way,  there  was  one 
tree  living  for  each  1.6  flowers  pollinated,  or  one  tree  for  every  2.18 
seeds  planted,  or  one  tree  for  every  1.35  seeds  germinated.  These 
computations  are  from  aggregates,  but  of  course  the  divisions  of  the 
group  for  the  different  years  are  scarcely  comparable  because  of  the 
age  difference.  Seedlings  from  crosses  of  1909  have  weak  seedlings 
more  completely  eliminated  and  have  been  subject  to  the  attacks  of 
disease  for  a  longer  period ;  hence  the  numerical  relation  between  seeds 
germinated  and  seedlings  living  may  naturally  be  expected  to  be  quite 

TABLE  3. — NUMERICAL  RELATION  OF  TREES  LIVING  TO  SEEDS  GERMINATED  IN 
GROUP  1,  ORCHARD  VARIETIES  X  ORCHARD  VARIETIES,  WITH  PERCENTAGES 
AND  AGES  OF  TREES 


Year 

Seeds 
germinated 

Number  of 
trees  living 

Percentage  of 
trees  living 

Age  of  trees, 
yrs. 

1909  

546 

424 

77.65 

7 

1911  

732 

526 

71.85 

5 

1912  

365 

218 

59.72 

4 

1913  

898 

660 

73  49 

3 

1914..            .      . 

1  041 

726 

68  04 

2 

1915  

425 

398 

93.64 

1 

different  from  that  of  the  one-year-old  lot  resulting  from  crosses  of 
1915.  The  relation  of  trees  living  to  seeds  germinated  may  be  shown 
most  accurately  by  years  in  Table  3.  Whether  the  percentages  given 
in  the  tabulation  are  high  or  low  depends  somewhat  upon  the  point 
of  view,  but  it  is  believed  that,  when  the  nature  of  the  plants  is  con- 
sidered, the  percentages  of  living  trees  are  approximately  what  may 
be  reasonably  expected.  There  are  differences  between  the  years 
and  it  appears  that  the  percentage  for  1909  is  higher  than  that  for  any 
other  year,  when  the  age  of  the  trees  is  considered.  For  the  year 
1909,  546  seeds  germinated  out  of  1,643  planted,  or  33.23  percent. 
The  seedlings  were  grown  in  the  nursery  three  years  before  planting  in 
the  orchard,  during  which  period  42  trees  died;  this  is  7.69  percent  of 
the  number  that  germinated.  In  the  spring  of  1913  the  survivors,  504 
in  number,  were  planted  in  the  orchard,  and  during  the  four  years 
since  there  has  been  a  loss  of  80  trees,  or  15.87  percent  of  the  number 
planted.  This  brings  the  total  loss  from  time  of  germination  to  122 
trees,  or  22.34  percent  of  the  number  germinated.  The  loss  of  trees 
in  the  orchard  was  due  almost  entirely  to  attacks  of  blight;  probably 
some  trees  were  inherently  weak  and  particularly  susceptible  to  the 
disease. 

From  the  crosses  of  1915  there  are  398  seedlings  living  of  the 
original  425;  this  is  93.64  percent,  but  there  will  be  losses  in  each  of 
the  succeeding  years  and  it  may  be  questioned  whether  or  not  the 
percentage  at  the  end  of  the  seventh  year  will  exceed  that  for  the 


392  BULLETIN  No.  275  [June, 

seedlings  of  1909.  The  seedlings  of  all  other  years  now  have  percentages 
of  living  trees  less  than  that  shown  for  the  seven-year-old  seedlings  and 
during  the  two  to  four  years  before  they  attain  the  age  of  seven  they 
will  sustain  losses  that  must  increase  the  existing  difference. 

In  each  of  the  six  years  there  were  wide  differences  in  the 
behavior  of  different  parental  combinations.  Some  combinations  stood 
much  lower  than  others  both  in  percentages  of  seeds  germinated  and 
in  percentages  of  trees  living;  these  combinations,  as  a  rule,  produced 
trees  that  were  manifestly  inferior  to  those  of  other  combinations,  and 
the  whole  performance  seems  to  indicate  that  these  particular  com- 
binations of  parents  are  undesirable.  There  was  nothing  in  appear- 
ance of  varieties,  or  in  anatomical  structure  of  floral  parts,  to  suggest 
causes  of  unsatisfactory  behavior,  and  it  must  be  concluded  that 
these  causes  lie  in  factors  of  constitution  that  have  descended  from 
the  unknown  ancestors. 

Of  the  35  orchard  varieties  represented  in  the  149  combinations 
attempted  in  this  group  of  orchard  varieties  X  orchard  varieties,  31 
have  been  used  as  pistillate  parents,  26  of  which  bore  fruit.  Twenty- 
eight  varieties  have  been  used  as  pollen-bearing  parents.  Four  varieties 
were  used  only  on  the  female  side,  and  six  only  on  the  male  side. 
There  were  55  attempted  matings  that  failed  entirely  and  6  of  the 
varieties  used  in  these  attempted  combinations  do  not  appear  in  com- 
binations that  produced  fruits.  Thus  94  matings  that  yielded  fruits 
involve  29  varieties.  Most  of  the  55  matings  that  failed  entirely 
involved  flowers  in  such  small  numbers  that  the  failures  cannot  be 
regarded  as  an  index  of  the  possibilities  of  the  respective  matings. 
They  were  made  in  the  greenhouse  on  potted  trees  flowering  for  the 
first  time  and  each  producing  only  one  or  two  clusters  with  only  two, 
or,  at  the  most,  three  emasculations  in  each  cluster. 

Individual  Records  in  Group  1 

Results  from  the  94  matings  yielding  fruits  are  so  various  in 
ratios  of  fruits  to  flowers  pollinated,  in  seed  production  of  fruits,  and 
in  numbers  of  living  seedlings  that  consideration  in  groups  is  not 
desirable;  perhaps  the  best  that  can  be  done  is  to  select  a  few  repre- 
sentative varieties  used  as  mothers  and  give  for  each,  in  tabular  form, 
the  results  obtained  as  mated  with  various  pollen  producers.  Examine 
first  Oldenburg  in  its  relation  to  nine  different  pollen  plants  as  in 
Table  4. 

Percentages  of  successful  pollinations  range  from  5.61  for  the 
cross  Oldenburg  X  Domine,  and  6.12  for  the  cross  Oldenburg  X  Rome, 
to  74.47  for  the  cross  Oldenburg  X  Hall's  No.  6,  and  72.92  for  the 
cross  Oldenburg  X  Shackleford.  While  it  required  the  pollination  of 
only  1.34  flowers  for  the  production  of  one  fruit  in  the  cross  Olden- 
burg X  Hall's  No.  6,  it  required  pollination  of  17.83  flowers  to  produce 


1986] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


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394  BULLETIN  No.  275  [June, 

one  fruit  in  the  cross  Oldenburg  X  Domine  and  16.33  flowers  for  one 
fruit  in  the  cross  Oldenburg  X  Rome.  The  extremes  are  sufficiently 
remote  to  indicate  rather  wide  differences  in  the  crosses  cited.  The 
cross  Oldenburg  X  Domine  which  has  the  lowest  percentage  of  suc- 
cessful pollinations  is  also  lowest  in  seed  production;  the  six  fruits 
yielded  26  seeds,  an  average  of  4.33  to  each  fruit.  The  highest  average 
seed  production  falls  to  the  cross  Oldenburg  X  Summer  Pound  Royal ; 
this  average  is  7.87  seeds  to  each  fruit,  very  little  above  the  average 
previously  given  for  open  pollinated  fruits.  No  one  of  the  crosses  has 
high  seed  production  and  for  most  it  may  be  rated  as  low.  In  germina- 
tion of  seeds,  five  of  the  crosses  have  percentages  below  50,  the  other 
four  range  from  69.09  percent  to  82.21  percent.  The  average  percent- 
age for  all  of  the  crosses  is  56.75,  which  is  somewhat  below  the  expec- 
tation for  this  group  of  crosses. 

In  persistence  of  the  seedlings  there  were  considerable  differences 
between  the  crosses.  The  cross  with  Rome  ranked  lowest  with  5 
of  the  original  9  seedlings  persisting  at  four  years  of  age;  this  is 
55.5  percent  of  the  germinations;  the  next  higher  percentage  is  59.52 
for  the  cross  with  Summer  Pound  Royal ;  here  there  were  42  germina- 
tions, from  which  25  seedlings  were  living  at  the  end  of  the  fourth 
year.  Crosses  of  1913  with  Fanny  and  Ben  Davis  stand  next;  in 
these  crosses  the  numbers  involved  were  somewhat  larger,  and  after 
two  years  in  nursery  and  one  year  in  orchard  the  percentages  of  living 
seedlings  are  75.14  percent  for  the  cross  with  Fanny,  and  86.56  percent 
for  the  cross  with  Ben  Davis.  Next,  with  seedlings  five  years  old  is 
the  cross  with  Shackleford  which,  from  152  seeds  germinated,  now  has 
135  seedlings  living,  or  88.88  percent.  The  remaining  four  crosses  of 
1909  have  seedlings  now  seven  years  old  and  well  established  in 
orchard ;  the  percentages  of  seeds  germinated  that  are  now  represented 
by  living  seedlings  are  as  follows:  cross  Oldenburg  X  Domine,  80  per- 
cent; Oldenburg  X  Hall's  No.  6,  82.3  percent;  Oldenburg  X  Twenty 
Ounce,  88.13  percent;  and  Oldenburg  X  Yellow  Transparent,  90.32 
percent.  For  this  Oldenburg  group  of  crosses  the  percentages  of  seed- 
lings that  have  lived  to  become  established  in  orchard  are  reasonably 
satisfactory. 

As  a  second  illustration  of  performance  in  crossing,  those  com- 
binations in  which  Rome  appears  as  the  pistillate  parent  may  be  tabu- 
lated as  for  the  Oldenburg  group  (Table  5).  Twelve  varieties  were 
used  as  pollenizers  and  the  crosses  were  made  in  five  successive  years. 
The  percentages  of  successful  pollinations  range,  in  this  group,  from 
8.11  percent  for  the  mating  with  Isham  in  which  pollination  of  37 
flowers  yielded  but  3  fruits,  to  77.28  percent  for  the  mating  with 
Collins  in  which  34  fruits  were  produced  from  44  flowers  pollinated. 
This  last  percentage  is  the  highest  obtained  from  any  pair  of  orchard 
varieties.  Next  to  the  cross  Rome  X  Collins  stands  Rome  X  Osimoe 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


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396  BULLETIN  No.  275  [June, 

with  a  percentage  of  74;  other  crosses  range  far  below  the  high  per- 
centages given  and  the  general  average  for  all  matings  with  Rome  is 
only  34.83  percent,  as  compared  with  40.85  percent  for  the  group  of 
Oldenburg  crosses.  The  12  Rome  crosses  exceed  the  9  Oldenburg 
crosses  in  numbers  of  flowers  pollinated  by  18,  but  the  Oldenburg 
group  has  26  more  fruits  than  has  the  Rome  group.  In  the  Olden- 
burg group  1  fruit  was  obtained  for  each  2.44  flowers  pollinated,  while 
in  the  Rome  group  2.87  flowers  were  pollinated  for  each  fruit  picked. 

The  average  seed  production  in  this  group  of  Rome  crosses  is 
6.72  seeds  to  each  fruit;  the  range  is  from  4  seeds  to  each  fruit  for 
Rome  X  Isham  to  8.37  seeds  to  each  fruit  for  Rome  X  Shackleford, 
the  maximum  more  than  twice  the  minimum.  The  loss  of  seeds 
between  the  time  when  taken  from  the  fruit  and  planting  was  almost 
exactly  10  percent,  distributed  among  7  of  the  crosses  and  ranging 
from  1.5  percent  for  the  cross  Rome  X  Shackleford  to  42.62  percent 
for  the  cross  Rome  X  Grimes.  For  5  of  the  crosses  there  were  no 
losses  of  seed.  Germination  in  this  group  of  crosses  is  good  in  relation 
to  germination  in  other  groups;  for  5  of  the  12  crosses  the  degree 
of  success  is  above  80  percent  and  only  1  rates  as  very  low;  that  is, 
Rome  X  Isham,  in  which  cross  only  3  of  the  12  seeds  from  3  fruits 
germinated.  The  maximum  germination  is  recorded  for  the  cross 
Rome  X  Ben  Davis,  in  which  31  of  the  36  seeds  planted  germinated. 
The  percentage  for  all  crosses  is  70.54,  which,  compared  with  the 
56.75  percent  for  the  Oldenburg  crosses,  shows  a  distinctly  better  per- 
formance on  the  part  of  the  Rome  group  of  crosses. 

As  regards  persistence  of  seedlings  this  group  of  Rome  crosses 
does  not  compare  favorably  with  the  Oldenburg  crosses.  The  losses 
for  the  Oldenburg  group  up  to  this  time  amount  to  17.3  percent,  while 
for  the  Rome  group  the  losses  have  reached  31.19  percent.  The  actual 
difference  between  the  groups  in  this  regard  is  even  greater  than  is 
shown  by  the  loss  percentages  because  of  the  greater  age  of  the  Olden- 
burg seedlings,  more  than  one-third  of  which  are  seven  years  old,  and 
the  group  contains  no  one-year-old  seedlings.  The  maximum  age  of 
Rome  seedlings  is  five  years  and  that  age  is  represented  only  by  the 
cross  Rome  X  Winter  Rambo  which  has  33  trees,  and,  further,  in  the 
cross  Rome  X  Shackleford  the  seedlings  are  only  one  year  old;  the 
percentage  of  trees  living  in  this  cross  is  95.37,  but  by  the  time  they 
attain  three  years,  which  is  the  minimum  age  in  the  Oldenburg  group, 
it  is  probable  that  this  high  percentage  will  be  much  reduced. 

Comparisons  between  the  different  crosses  in  this  Rome  group 
are  not  satisfactory  because  of  differences  in  age  of  living  seedlings, 
differences  in  numbers  of  fruits  and  seeds,  and  the  additional  fact  that 
only  the  results  of  one  season  are  recorded  for  each  cross.  Any  one 
of  the  crosses  tabulated,  if  repeated  in  another  season  might,  and 
probably  would,  give  quite  different  results  in  percentages  of  success- 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  397 

fill  pollinations,  seed  production,  and  seed  germination,  these  different 
results  being  due  to  some  slight  seasonal  difference  in  the  vigor  of 
one  or  the  other  of  the  plants  mated.  This  seasonal  variation  is  some- 
thing affecting  all  varieties,  but  all  varieties  are  not  affected  in  the 
same  way  in  any  particular  season. 

Various  causes  may  act  to  produce  the  differences,  which,  altho 
often  intangible  or  unobserved,  are  sufficient  to  impair  the  results  or 
entirely  inhibit  successful  crossing  between  two  individuals.  Slight 
differences  in  the  situations  occupied  by  two  trees  which  it  is  proposed 
to  cross  and  which  subject  one  to  different  air  currents,  water  supply, 
or  soil  fertility  from  the  other,  may  react  to  modify  the  development 
of  stamens  and  pistils  and  so  diminish  the  vitality  of  parts  that  they 
are  incapable  of  performing  proper  functions.  Differences  in  per- 
formance in  fruit  production  the  preceding  year  may  enhance  the 
vitality  of  one  and  diminish  that  of  the  other  even  tho  both  bloom 
abundantly  and  appear  normal.  It  has  been  frequently  observed  that 
an  individual  producing  abundant,  perfect  pollen  in  one  season  may, 
the  following  season,  have  pollen  deficient  in  quantity  and  with  an 
increased  proportion  of  defective  grains;  so  too,  the  vigor  of  pistils  as 
evidenced  by  position,  robust  structure,  and  evident  receptiveness  may 
have  these  qualities  in  less  marked  degree  in  another  year.  Because 
of  a  slight  difference  in  degree  of  advancement  of  buds  in  spring,  a 
frost  may,  without  killing,  injure  those  of  one  of  a  proposed  pair, 
leaving  those  of  the  other  uninjured.  These  are  only  a  part  of  the 
causes  accountable  for  differences  in  the  results  obtained  with  par- 
ticular crosses,  but  that  seasonal  differences  are  of  common  occurrence 
is  well  understood  by  those  who  have  practiced  crossing  apple 
varieties,  and  the  existence  of  these  differences  suggests  caution  in 
basing  judgment  regarding  the  desirability  of  any  particular  cross 
upon  the  performance  of  a  single  season. 

As  further  illustration  of  the  behavior  of  particular  crosses 
between  orchard  varieties,  the  results  obtained  with  Wythe  and 
Shackleford  as  mother  plants  are  tabulated  (Table  6).  For  Wythe 
there  are  seven  crosses  representing  six  combinations;  the  1913  cross 
with  Rome  being  repeated  in  1915;  these  crosses  are  distributed  in 
three  years  and  the  resulting  seedlings  are  now  one,  three,  and  five 
years  old.  For  Shackleford  (Table  7)  there  are  also  seven  crosses 
representing  six  combinations;  the  1909  cross  with  Oldenburg  being 
repeated  in  1911;  these  crosses  are  distributed  over  five  years  and  the 
various  lots  of  seedlings  are  two  to  six  years  old. 

These  two  groups  of  crosses  show  the  same  irregularities  found 
in  the  Oldenburg  and  Rome  groups.  Percentages  of  successful  pol- 
linations range  for  the  Wythe  group,  from  14.28  for  the  1913  cross 
with  Rome,  to  52.08  for  the  1915  cross  with  Collins;  none  of  them 
are  high,  the  average  percentage  for  all  being  29.39.  For  the  Shackle- 


398 


BULLETIN  No.  275 


[June. 


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1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  399 

ford  group  the  range  of  percentages  of  successful  pollinations  is  still 
wider,  the  minimum  being  2.00  for  the  cross  with  Jonathan,  and  the 
maximum  64.58  for  the  cross  with  Grimes;  six  of  the  seven  crosses 
must  be  regarded  as  having  very  low  degrees  of  success,  and  the 
average  for  the  group  is  only  18.71  percent.  Altho  the  maximum  of 
successful  pollinations  is  attained  in  the  cross  Shackleford  X  Grimes 
of  the  Shackleford  group,  the  average  for  all  crosses  of  the  group  is 
considerably  below  the  average  for  crosses  of  the  Wythe  group — 18.71 
for  the  Shackleford  group  and  29.39  for  the  Wythe  group.  In  the 
matter  of  seed  germination  the  difference  between  the  two  groups  is 
still  greater;  the  percentage  of  seeds  germinated  in  the  Wythe  group 
is  81.69  and  only  59.09  in  the  Shackleford  group.  Persistence  of  seed- 
lings is  not  materially  different  in  the  two  groups.  The  percentages 
of  seedlings  living  in  November,  1916,  were  74.20  for  the  Shackleford 
group  and  76.98  for  the  Wythe  group,  an  apparent  slight  advantage 
for  the  Wythe  group,  but  bearing  in  mind  that  about  45  percent  of  the 
Wythe  seedlings  were  only  one  year  old  and  that  only  about  28  percent 
of  the  Shackleford  seedlings  were  in  the  youngest  lot,  and  these  two 
years  old,  it  is  perhaps  best  to  assume  the  groups  to  be  equal  in  per- 
sistence of  seedlings. 

GROUP  2:  ORCHARD  VARIETIES  X  CRAB-LIKE  FORMS  OF  MALUS 

There  are  gathered  together  in  this  group  all  attempts  to  hybri- 
dize in  which  the  pistillate  parent  is  an  orchard  variety  and  the  pollen- 
bearing  parent  a  crab,  or  a  crab-like  form  of  some  species  of  Malus. 
Many  of  the  matings  have  been  between  extremes  of  Malus  forms; 
some  of  the  pollen  plants  are  shrubs  rather  than  trees,  and  some  have 
fruits  no  larger  than  peas;  while  in  some  the  leaves  are  variously 
lobed,  and  in  others,  glabrous.  In  some  the  calyx  lobes  are  regularly 
deciduous;  in  some  the  lobes  are  persistent  and  in  still  others  the 
individual  carries  fruits,  some  of  which  have  the  lobes  deciduous  while 
on  other  fruits  they  persist.  There  are  also  wide  differences  in  num- 
bers of  carpels  in  the  ovary,  in  fruit  and  foliage  coloring,  in  length  of 
pedicels,  in  manner  in  which  fruits  are  borne,  in  season  of  maturity  of 
fruits,  and  in  numbers  of  petals,  stamens,  and  styles. 

Hybridizing  Work  of  Dr.  Saunders  and  Others 

Of  the  breeding  possibilities  of  most  of  these  diverse  forms  little 
appears  to  be  known.  The  statement  that  they  hybridize  readily  is 
common,  but  there  are  few  accounts  of  systematic  attempts  to  breed 
together  particular  species  or  forms,  and  these  involve  only  a  small 
number  of  the  many  kinds  available.  In  1888  Professor  John  Craig, 
then  at  the  Iowa  Agricultural  College,  hybridized  Malus  toringo  by 


400  BULLETIN  No.  275  [June, 

pollen  of  Wythe,  and  Mains  ringo  with  pollen  of  Oldenburg.1  In  1896 
report  on  these  hybrids  was  made  by  Professors  J.  L.  Budd  and  N.  E. 
Hansen2  as  follows: 

"The  hybrids  of  Pyrus  Toringo  and  Pyrus  Ringo  crossed  with  Wythe  and 
Duchess  pollen  have  fruited,  but  the  fruit  has  little  if  any  value.  Pyrus  Toringo 
pollinated  with  Duchess  produced  seedlings  with  upright  habit  and  much  modi- 
fied foliage.  The  fruit  resembles  Duchess  in  shape  and  striping,  but  is  not  larger 
than  a  small  crab  and  ripens  earlier  than  either  parent.  This  cross  is  a  violent 
one,  as  the  Pyrus  Toringo  is  a  bush  species  from  east  Europe  with  small  cut 
leaves  and  fruit  not  larger  than  a  marrowfat  pea.  Our  experience  and  that  of 
others  in  Europe  and  America  lead  to  the  belief  that  such  violent  crosses  rarely 
if  ever  give  valuable  results.  Our  most  pronounced  successes  have  been  with 
nearly  allied  varieties  or  species." 

In  1894  Dr.  William  Saunders,  then  Director  of  the  Central  Experi- 
mental Farm,  Ottawa,  Canada,  began  hybridizing  Mains  baccata  and 
the  best  orchard  varieties  grown  in  Ontario.  This  work  was  under- 
taken with  a  view  to  the  production  of  varieties  of  sufficient  hardiness 
to  resist  the  climatic  extremes  of  the  northwestern  plains  provinces  of 
Canada.  Seedlings  of  Mains  baccata  grown  from  seeds  obtained  from 
the  Royal  Botanic  Garden  at  St.  Petersburg,  Russia,  had,  thru  a  test 
of  several  years,  proved  hardy  at  plains  stations,  and  flowers  of  these, 
as  mother  plants,  were  pollinated  with  pollen  from  the  selected 
varieties. 

Dr.  Saunders  in  1911  gives  an  account  of  the  work  in  a  bulletin3 
entitled,  "Progress  in  the  Breeding  of  Hardy  Apples  for  the  Canadian 
Northwest,"  and  from  this  the  following  quotations  are  of  interest 
here: 

"This  work  was  begun  in  1894  and  has  since  been  continued  along  several 
different  lines.  The  seeds  obtained  from  the  first  crosses  were  sown  in  the 
autumn  of  that  year  and  germinated  in  the  following  spring,  producing,  in  all, 
about  160  young  trees.  ...  In  1899  thirty-six  of  the  cross-bred  apples  first  pro- 
duced and  grown  at  Ottawa  fruited,  and  five  of  them  were  of  such  size  and 
quality  as  to  justify  their  being  propagated  for  more  general  test.  The  cross- 
bred sorts  grafted  on  roots  of  seedlings  of  Pyrus  baccata  have  produced  trees 
which,  so  far  as  they  have  been  tried,  seem  to  be  quite  as  hardy  as  the  wild  form 
of  baccata.  There  seems  every  reason  to  expect  that  they  will  prove  generally 
hardy  thruout  the  northwestern  country. 

"In  1896  a  series  of  crosses  was  begun  on  another  sort  of  wild  crab,  known 
as  Pyrus  prunifolia.  ...  Its  hardiness  in  the  Northwest  has  also  been  established 
by  a  test  covering  a  number  of  years  on  both  of  the  experimental  farms  at 
Brandon  and  Indian  Head.  The  first  crosses  with  this  species  were  made  in  1896 
and  since  then  many  new  sorts  have  thus  been  originated.  .  .  . 

"Another  line  of  work  in  producing  new  apples  was  begun  in  1902,  in 
crossing  Pyrus  Mains,  the  wild  apple  of  Europe,  with  some  of  the  best  Canadian 
sorts.  This  fruit  is  about  an  inch  in  diameter  to  start  with,  and  of  fair  quality. 
A  hardy  form  of  this  tree  has  been  secured  which  has  stood  several  winters  at 


'Iowa  Agr.  Exp.  Sta.  Bui.  14,  189.  1891. 
2Iowa  Agr.  Exp.  Sta.  Bui.  32,  498.  1896. 
'Canad.  Cent.  Exp.  Farm  Bui.,  68.  1911. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  401 

Brandon  and  Indian  Head  without  injury,  and  with  this  additional  crosses  have 
been  made.  .  .  .  Many  of  the  best  of  the  crosses  produced  on  P.  baccata  and 
P.  prunifolia  have  been  recrossed,  thus  introducing  a  second  quota  of  the  blood 
of  the  larger  apple  with  the  hope  of  obtaining  fruits  of  larger  size  and  higher 
quality.  Regarding  these  there  is  as  yet  not  much  proof  that  they  are  suffi- 
ciently hardy  to  endure  the  climate  of  the  Northwest;  this  can  only  be  fully 
determined  by  further  experiment.  Two  varieties  of  these  crosses  of  Ontario 
and  Spy  have  been  tested  for  several  years  at  Indian  Head,  but  have  not  yet 
fruited.  Thus  far  they  have  been  fairly  hardy." 

Dr.  Saunders  gives  brief  descriptions  of  seventeen  named  hybrids 
derived  from  pollinations  of  Mains  baccata  by  nine  different  orchard 
varieties;  these  fruits  exhibit  various  color  combinations  and  average 
1.5  inches  in  diameter.  A  further  list  of  thirteen  named  baccata 
hybrids  is  given,  but  the  fruits  are  said  to  be  less  desirable  than  those 
of  the  first  list.  Hybrids  between  Mains  prunifolia  and  four  orchard 
varieties  are  represented  in  a  list  of  ten  named  varieties,  fruits  of 
which  range  from  1.5  inches  to  a  little  more  than  2  inches  in  diameter, 
with  an  average  diameter  of  1.82  inches.  Trees  of  the  baccata  hybrids 
were  distributed  to  settlers  in  various  parts  of  the  western  provinces 
in  1902  and  1903. 

At  the  close  of  the  bulletin  Dr.  Saunders  sums  up  as  follows: 

"Since  the  first  seeds  of  Pyrus  baccata  were  obtained  from  the  Royal 
Botanic  Gardens,  St.  Petersburg,  Russia,  in  1887,  twenty-four  years  have  passed. 
As  shown  by  the  facts  submitted  in  this  bulletin,  during  this  time  a  large 
number  of  experiments  have  been  carried  on  with  varying  success,  and  the 
indications  are  that,  by  persevering  along  the  lines  laid  down,  in  a  very  few 
years  a  number  of  varieties  of  apples  will  be  available  possessing  that  hardiness, 
size,  and  quality  which  will  commend  them  to  the  settlers  in  all  those  portions 
of  the  northern  country  where  ordinary  apples  under  average  conditions  cannot 
be  grown.  The  success  thus  far  achieved  is  most  encouraging  and  doubtless 
greater  triumphs  in  the  future  will  reward  persistent  efforts." 

The  work  thus  far  done  at  the  Illinois  Station  is  only  the  begin- 
ning of  an  attempt  to  ascertain  the  possibilities  of  the  various  forms  of 
Malus  as  breeding  material.  Flowers  of  certain  of  the  common  orchard 
varieties  have  been  pollinated  with  pollen  from  as  many  diverse  forms 
as  chanced  to  be  available,  in  order  to  test  the  behavior  of  each  in  its 
relation  to  the  particular  variety.  Thus  flowers  of  Grimes  have  been 
pollinated  with  pollen  of  16  different  Malus  forms,  Jonathan  with  14, 
Oldenburg  with  9,  Tolman  with  10,  Winesap  with  21,  Yellow  Trans- 
parent with  11,  and  others  with  smaller  numbers.  Results  have  been 
various;  some,  in  fact  a  considerable  portion  of  the  attempts,  failed 
entirely,  while  others  were  in  varying  degrees  successful.  All  should 
be  repeated  before  judgment  is  expressed  as  to  possible  performance, 
and  the  greater  the  number  of  repetitions  the  better  the  basis  for  an 
opinion  regarding  what  may  be  expected  of  a  particular  mating.  As 
examples  of  this,  these  facts  may  be  cited:  Grimes  X  Yellow  Siberian 
Crab  (857)  in  1912  failed  utterly,  but  the  same  mating  in  1914  was 


402 


BULLETIN  No.  275 


[June, 


38  percent  successful;  Grimes  X  Mains  floribunda  (821)  was  26  per- 
cent successful  in  1914  and  failed  entirely  in  1915;  Grimes  X  Mains 
mains  var.  (19667),  a  crab  form  of  uncertain  taxonomic  position,  gave 
34  percent  successful  pollinations  in  1914  but  gave  no  fruits  in  1916. 


TABLE  8.- 


-  VARIETIES  USED  AS  PISTILLATE  PARENTS  IN  GROUP  2,  ORCHARD 
VARIETIES  X  CRAB-LIKE  FORMS  OF  MALUS 


Variety 


Number 

of 
matings 


Number  of 
distinct 
parental 
combi- 
nations 


Flowers 
pollinated 


Fruits 
matured 


1  Akin 11 

2  Arkansas 2 

3  Ben  Davis 8 

4  Black  Ben  Davis 1 

5  Collins 4 

6  Delicious 6 

7  Domine 5 

8  Early  Ripe 1 

9  Fameuse 6 

10  Fanny 6 

11  Golden  Sweet 1 

12  Grimes 22 

13  Huntsman 3 

14  Jefferis 2 

15  Jonathan 18 

16  Lady 1 

17  Longfield 4 

18  Mclntosh 1 

19  Melonen 1 

20  Oldenburg. 13 

21  Oliver 5 

22  Osimoe 4 

23  Red  Astrachan 1 

24  Roe's  Duchess 2 

25  Rome 10 

26  Shackleford 3 

27  Stayman  Winesap 10 

28  Summer  P.  Royal 6 

29  Tolman " 13 

30  Twenty  Ounce 3 

31  Willow 3 

32  Winesap 28 

33  Winter  Rambo 1 

34  Wythe 1 

35  Yellow  Transparent 13 

Total..  219 


2 
7 
1 
3 
4 
5 
1 
5 
5 
1 

16 
3 
2 

14 
1 
4 
1 
1 
9 
4 
4 
1 
2 
7 
3 
8 
5 

10 
2 
3 

21 
1 
1 

11 


119 
100 
626 

48 
195 

51 
119 

50 
135 

50 

51 
712 
145 

86 

646 

4 

189 

46 

46 
215 

59 

189 

3 

99 
686 
150 

99 
248 
493 

57 
146 
778 

48 

48 
216 


4 
1 

72 
1 
2 
0 
3 
0 
8 
0 
7 

87 

19 
0 

151 
0 

68 
6 

12 

62 
3 

16 
1 

49 
303 

47 
4 

23 

102 

1 

6 

28 
0 
5 

10 


176 


6  952 


1  101 


These  cases  occur  so  frequently  that  they  show  clearly  the  futility  of 
attempting  to  judge  the  desirability  of  particular  matings  from  results 
of  one  season. 

Varieties  Used  as  Pistillate  Parents  in  Matings  of  Group  2 

The  varieties  utilized  as  pistillate  parents  in  this  group,  orchard 
varieties  X  crab-like  forms  of  Mains,  are  tabulated  in  alphabetical 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  403 

order  in  Table  8.  They  number  thirty-five.  Each  is  given  the  num- 
ber of  matings,  the  number  of  distinct  parental  combinations,  number 
of  flowers  pollinated,  and  of  fruits  matured. 

In  a  considerable  number  of  cases  the  same  combination  was 
attempted  in  more  than  one  year,  so  that  the  actual  number  of  matings 
was  219  but  the  distinct  combinations  of  parents  only  176.  For  the 
varieties  Akin,  Delicious,  Fanny,  Lady,  Red  Astrachan,  Oliver,  and 
Stayman  Winesap,  all  flowers  pollinated  were  those  of  small  potted 
trees  forced  in  the  greenhouse.  For  the  varieties  Domine,  Fameuse, 
Grimes,  Jonathan,  Oldenburg,  and  Winesap,  part  of  the  pollinations 
were  in  the  greenhouse  and  part  in  the  orchard.  For  all  other  varieties 
the  pollinations  were  wholly  on  trees  in  orchard.  It  may  be  noted 
that  six  varieties — namely,  Delicious  with  four  matings  and  51  flowers 
pollinated,  Early  Ripe  with  one  mating  and  50  flowers,  Fanny  with  5 
matings  and  50  flowers,  Jefferis  with  two  matings  and  86  flowers, 
Lady  with  one  mating  and  four  flowers,  and  Winter  Rambo  with  one 
mating  and  48  flowers — failed  entirely. 

Four  varieties — Arkansas,  Black  Ben  Davis,  Red  Astrachan,  and 
Twenty  Ounce,  with  six  matings  and  an  aggregate  of  208  flowers  pol- 
linated— yielded  only  one  fruit  each;  a  number  of  other  varieties  gave 
very  low  percentages  of  success.  However,  if  the  6,952  flowers  pol- 
linated within  the  group  should  be  considered  in  relation  to  the  1,101 
fruits  matured,  it  appears  that  the  ratio  1  fruit  for  each  6.31  flowers 
pollinated  is  higher  than  the  ratio  1  to  7.70  obtained  from  the  aggre- 
gates of  fruits  and  flowers  of  the  group  orchard  varieties  X  orchard 
varieties.  In  this  latter  group  a  distinctly  higher  ratio  would  naturally 
be  expected  because  of  greater  similarity  between  the  plants  mated, 
than  would  be  expected  where  the  plants  paired  exhibit  such  extremes 
in  important  characters  as  is  the  case  in  the  group  orchard  varieties 
X  crab-like  forms. 

Forms  o/  Mains  Used  as  Pollen  Parents  in  Matings  of  Group  2 

The  species  and  varieties  supplying  pollen  for  the  matings  in  this 
group  number  thirty-two.  Table  9  shows  them  arranged  in  order  of 
the  number  of  matings  in  which  used,  together  with  the  number  of 
varieties  on  which  each  was  used,  the  number  of  flowers  pollinated, 
and  the  number  of  fruits  produced. 

These  32  forms  of  Malus  supplied  pollen  for  the  176  distinct 
combinations  of  parents;  12  of  them  used  twenty-six  times  on  25 
varieties  and  involving  the  pollination  of  184  flowers  failed  to  effect 
fertilization,  or  at  least  developed  no  fruits.  The  number  of  matings 
was  219  and  of  these  115,  involving  1,990,  or  28.62  percent  of  the 
flowers  pollinated,  failed.  Of  the  176  distinct  parental  combinations 
81,  including  1,493  flowers  pollinated,  or  21.48  percent  of  the  total 
pollinations,  failed;  fruit  production  was  then  distributed  among  94 


404 


BULLETIN  No.  275 


[June, 


distinct  parental  combinations  and  followed  pollination  of  5,459,  or 
78.52  percent  of  all  flowers  used.  All  the  fruits  produced,  1,101  in 
number,  came  from  104  matings  and  followed  pollination  of  4,962,  or 
71.38  percent  of  all  flowers  used. 

TABLE  9. — POLLEN  PARENTS  IN  GROUP  2,  ORCHARD  VARIETIES  X  CRAB-LIKE 

FORMS  OF  MALUS 


Species  or  variety 

Times 
used 

Number 
of  vari- 
ties  on 
which 
used 

Flowers 
polli- 
nated 

Fruits 
matured 

1  M.  ringo  (840  &  19662)  

25 

11 

310 

13 

2  M  .  niedwietzkyana  (834)  

19 

14 

308 

32 

3  M.  floribunda  (821)  
4  M  .  prunifolia  var  (838)  
5  M.  siberica  frutico  coccinea  (19643)  

18 
17 
12 

12 

14 
12 

985 
991 
331 

205 
246 
25 

6  M.  microcarpa  (19644)  

13 

10 

134 

5 

7  M.  baccata,  red  fruit  (806)  
8  M.  Yellow  Siberian  Crab.  .  .  .  (857)  
9  M.  malus  var  (19667)  

12 

12 
9 

11 
9 
6 

537 
708 
135 

72 
132 
20 

10  M.  baccata  maxima  (810)  
11  M.  atrosanguinea  (804)  
12  M  .  sylvestris  fastigiata  bifera  (820)  

9 

7 
6 

8 
5 
5 

504 
275 
127 

55 
75 
16 

13  M.  Whitney  Crab  

6 

6 

290 

24 

14  M.  prunifolia  var  (856)  
15  M.  arnoldiana  (802)  
16  M.  baccata,  red  fruit,  late  ....  (807)  
17  M.  coronaria  (818)  
18  M.  baccata  sieboldi  

5 
4 
4 
4 
4 

5 
4 
4 
4 
4 

243 
150 
197 
22 
197 

67 
4 
41 
0 
25 

19  M.  Fluke  Apple  (822)  
20  M.  scheideckeri  (19646)  

4 
4 

4 
4 

16 

21 

0 
2 

21  M.  toringo  (852  &  19664)  

4 

4 

182 

10 

22  M.  soulardi  (846)  
23  M.  toringo  (851)  
24  M.  malus  fl.  pi....  (833)  
25  M  .  prunifolia  xanthocarpa  .  .  .  (839)  
26  M.  baccata  oblonga  (811)  
27  M.  sargenti  (843)  
28  M.  malus  pendula  (832)  
29  M.  halliana  (823)  
30  M.  ioensisfl.  pi  (826)  
31  M.  spectabilis  (848)  
32  M.  toringo  (843)  

3 
3 
3 
2 
2 
2 
2 
1 
1 
1 
1 

3 
2 
3 
2 
2 
2 
2 
1 
1 
1 
1 

21 
11 
143 
10 
17 
18 
14 
5 
4 
10 
36 

0 
0 
32 
0 
0 
0 
0 
0 
0 
0 
0 

Total.. 

219 

176 

6  952 

1  101 

Of  the  6,952  flowers  pollinated  5,912,  or  approximately  85  per- 
cent, were  on  trees  in  orchard  and  1,040,  or  about  15  percent,  were  on 
potted  trees  in  the  greenhouse.  Of  the  fruits  harvested,  1,050,  or  a 
little  over  95  percent,  were  from  pollinations  in  the  orchard,  while  51 
or  nearly  5  percent  were  from  the  house.  Examining  the  ratios,  how- 
ever, it  appears  that  the  ratio  of  success  inside  was  distinctly  higher 
than  that  for  outside  pollinations;  in  other  words  it  required  pollina- 
tion of  2.04  flowers  to  produce  one  fruit  in  the  house,  while  5.63  flowers 
were  used  to  produce  one  fruit  from  pollinations  in  orchard.  The 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  405 

division  of  the  219  matings  as  between  house  and  orchard  was  104,  or 
approximately  48  percent,  in  the  house,  and  114,  or  above  52  percent, 
in  the  orchard.  The  average  of  flowers  to  each  mating  is  exactly  10 
for  the  house  and  more  than  five  times  that  number,  or  nearly  52  for 
matings  in  orchard.  The  ratio  of  fruits  to  flowers  pollinated  is  higher 
for  the  house  than  for  the  orchard  as  is  also  the  percentage  of  matings 
that  failed  entirely. 

This  failure  of  a  much  greater  number  of  the  inside  matings  may 
be  ascribed,  in  part,  to  the  often  very  small  numbers  of  flowers  pol- 
linated, and  in  part  to  age  differences  between  the  trees  employed; 
the  orchard  trees  were  all  mature  and  well-established  in  fruit  pro- 
duction, while  those  used  in  the  greenhouse  were  all  young,  most  of 
them  flowering  for  the  first  time  and  producing  but  few  clusters  of 
flowers  that  were  not  infrequently  defective.  It  is  a  common  experi- 
ence that  young  apple  trees,  whether  growing  in  orchard  or  under 
glass,  fail  in  the  first  efforts  at  fruit  production.  They  produce  a  few 
flowers,  but  the  reproductive  function  is  still  subordinate  to  the  vege- 
tative function,  flowers  are  imperfect  in  structure  or  are  incapable  of 
performing  proper  functions;  hence,  pollination  of  such  flowers  fails. 
While  this  condition  is  almost  universal  with  young  trees  of  orchard 
varieties,  it  is  less  common  with  the  crab-like  species.  In  the  group 
under  consideration  the  pistillate  parents  are  all  orchard  varieties; 
the  plants  of  these  varieties  available  for  use  in  the  house  were  in 
great  part  young  trees  making  their  initial  effort  in  flower  production 
and  the  large  number  of  failures  is  due  doubtless  to  the  infertile  con- 
dition of  these  first  flowers. 

Performance  of  Certain  Orchard  Varieties  When  Pollinated  by 

Crab-like  Forms 

The  details  of  the  performance  of  a  few  of  the  orchard  varieties 
when  pollinated  with  pollen  of  crab-like  forms  may  be  given  briefly 
at  this  time,  beginning  with  Akin. 

Akin  is  represented  by  two  trees  from  scions  grafted  March  1, 
1910,  one  on  paradise,  the  other  on  Doucin  stock,  the  stocks  being 
then  in  8-inch  pots.  No  difference  in  growth  of  the  trees  that  could 
be  attributed  to  differences  in  stocks  had  been  observed ;  both  flowered 
in  March,  1914,  and  the  flowers  were  pollinated.  Neither  flowered 
in  1915  but  both  flowered  in  1916,  and  one  of  the  pair — the  one  on 
Doucin — flowered  again  in  1917.  On  March  14,  1914,  5  flowers  on 
the  tree  on  Doucin  stock  were  pollinated  with  pollen  from  M.  nied- 
wietzkyana  (834) ;  no  fruits  developed.  On  April  1  of  the  same  year, 
flowers  on  the  tree  on  paradise  stock  were  pollinated  as  follows:  4 
flowers  with  pollen  of  M.  ringo  (19662);  5  flowers  with  pollen  of 
M.  coronaria  (818);  and  5  flowers  with  pollen  of  M.  halliana  (823). 


406  BULLETIN  No.  275  t June, 

These  pollinations  also  failed.  Two  years  later,  in  March,  1916,  34 
flowers  on  the  tree  on  paradise  were  pollinated  with  pollen  of  M. 
ringo;  4  fruits  developed  which  yielded  33  seeds,  29  of  which  ger- 
minated. On  the  same  tree,  11  flowers  were  pollinated  with  pollen 
from  M.  soulardi  (846)  but  no  fruits  resulted.  Flowers  borne  by 
the  tree  on  Doucin  stock  were  pollinated  as  follows:  6  with  pollen  of 
M.  microcarpa  (19644) ;  6  with  pollen  of  M.  mains  var.  (19667) ;  18 
with  pollen  of  M.  siberica  frutico  cocdnea  (19643);  17  with  pollen 
from  M.  ringo  (840) ;  and  8  with  pollen  from  M.  niedmetzkyana 
(834),  a  total  of  55  flowers  with  five  distinct  pollen  parents;  no 
development  of  fruit  followed.  Thus  for  this  variety  there  were  119 
pollinations  by  eight  distinct  pollen  producers;  seven  of  the  eight 
failed  entirely,  and  one,  M.  ringo,  gave  4  fruits  from  34  flowers 
pollinated,  or  11.75  percent.  The  reciprocal  of  this  partially  successful 
cross  gave  13  fruits  from  27  pollinations,  or  approximately  48  percent 
success.  Reciprocals  of  the  crosses  with  M.  soulardi  and  M .  coronaria 
both  failed,  but  Akin  pollen  used  on  one  form  of  M .  prunifolia  was  14 
percent  successful,  and  on  M.  baccata  oblonga  6  of  7  flowers  pol- 
linated developed  fruits,  a  success  percentage  of  85.71.  The  small 
success  attained  in  the  role  of  mother  plants  is  not  due  to  any  inherent 
defect  in  the  variety,  but  to  immaturity  of  the  individuals  used. 
Orchard  trees  of  this  variety  now  in  the  tenth  year  from  the  graft 
have  not  flowered  and  it  is  believed  that  late  development  of  the 
reproductive  function  is  characteristic. 

Grimes  was  mated  twenty-two  times  with  16  different  forms  of 
Malus  as  pollenizers.  The  flowers  pollinated  aggregate  712  and  the 
fruits  matured  number  87,  giving  a  success  percentage  of  12.21.  Both 
orchard  and  greenhouse  pollinations  are  represented:  thirteen  matings 
were  on  trees  in  orchard  and  nine  on  young  trees  in  greenhouse.  All 
of  the  latter  failed,  as  did  also  four  of  the  orchard  matings.  Thus  the 
87  fruits  are  the  product  of  nine  orchard  matings.  The  percentages  of 
success  in  these  matings  range  from  2.08  for  the  cross  Grimes  X 
M.  prunifolia  (838),  with  48  flowers  pollinated  and  only  1  fruit  har- 
vested, to  42  percent  for  the  cross  Grimes  X  M.  baccata  (807),  with 
50  flowers  pollinated  and  21  fruits  matured.  The  four  orchard  matings 
that  failed  were:  a  1912  mating  with  Yellow  Siberian  Crab  (857),  with 
47  flowers  pollinated  (this  same  mating  in  1914,  with  50  flowers  pol- 
linated, was  38  percent  successful) ;  a  1913  mating  with  M.  atro- 
sanguinea  (804)  using  45  flowers  (repeated  in  1915  this  mating  gave 
5  fruits  from  43  pollinations) ;  a  1913  mating  with  M.  floribunda  (821) 
using  33  flowers  (this  repeated  in  1914  gave  13  fruits  from  50  flowers, 
or  a  success  percentage  of  26) ;  and  a  single  mating  in  1916  with  M. 
prunifolia  var.  (856) ,  with  49  flowers  pollinated. 

None  of  these  failures  were  attended  with  any  circumstances 
indicating  or  suggesting  causes  of  infertility.  The  partial  success 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  407 

attained  in  repetition  of  three  of  the  four  crosses  eliminates  any  sug- 
gestion of  habitual  infertility  between  the  plants  mated  and  in  these 
cases  cause  of  failure  must  be  held  to  rest  in  some  undetermined 
seasonal  or  local  condition.  The  cross  with  M.  prunifolia  var.  (838) 
was  not  repeated,  but  any  suspicion  of  defective  pollen  is  eliminated 
by  the  fact  that  pollen  from  the  same  dish  used  on  Longfield  stigmas 
gave  30  fruits  from  46  flowers  pollinated,  or  a  success  percentage  of 
more  than  65.  Failure  of  pollinations  in  the  greenhouse  is  ascribed 
in  part,  as  in  the  case  of  Akin,  to  the  use  of  first  flowers  borne  by 
young  trees.  In  part,  failure  may  have  been  due  to  violence  of  the 
cross,  for  in  the  two  matings  with  M.  niedwietzkyana  the  extremes 
of  Malus  forms  meet.  This  Turkestan  species,  because  of  its  very 
distinctive  characters,  has  been  used  as  a  pollenizer  in  19  matings  on 
14  varieties;  12  of  these  matings  on  7  varieties  have  failed,  and  7 
matings  on  7  varieties  have  given  percentages  ranging  from  3.4  for 
the  mating  with  Jonathan  to  50  percent  for  the  matings  with  Yellow 
Transparent.  Failure  of  Grimes  to  accept  pollen  of  this  species,  even 
for  two  matings  in  different  years,  does  not  definitely  establish  the 
relation  between  the  two  because  of  these  two  facts — the  small  num- 
bers of  flowers  pollinated  and  the  immaturity  of  the  Grimes  trees. 
Further  matings,  with  increased  numbers  of  pollinations  on  more 
mature  trees,  may  give  quite  different  results. 

Jonathan  was  mated  eighteen  times  with  14  species  and  varieties 
of  Malus.  The  aggregate  of  flowers  pollinated  was  646  and  the  fruits 
harvested  numbered  151;  this  gives  23.37  as  the  percentage  of  suc- 
cess with  a  ratio  of  1  fruit  for  each  4.27  flowers.  Eight  of  the  matings 
were  in  the  greenhouse  and  ten  in  the  orchard.  All  the  inside  pollina- 
tions were  on  a  single  Jonathan  tree,  pot-grown  from  graft  inserted 
March  5,  1913,  on  paradise  stock,  and  flowering  for  the  first  time  in 
March,  1916.  The  tree  bore  117  flowers,  all  of  which  were  pollinated. 
The  net  result  was  1  fruit  from  one  of  29  flowers  pollinated  by  M. 
niedwietzkyana;  this  contained  7  seeds,  5  of  which  germinated.  There 
was  complete  failure  in  three  of  the  ten  matings  in  the  orchard.  These 
failures  occurred  in  the  spring  of  1913,  and  the  pollen  plants  were 
M.  floribunda  (821)  with  47  pollinations,  M.  prunifolia  var.  (838) 
with  47,  and  M.  baccata  maxima  (810)  with  46;  no  other  matings 
between  Jonathan  and  members  of  the  crab  group  were  attempted  in 
that  year  and  no  satisfatory  reasons  for  the  failures  were  found. 
Pollen  of  M.  floribunda  (821)  failed  on  Grimes  in  the  season  of  1913, 
but  was  partially  successful  on  Fameuse;  pollen  of  M.  baccata 
maxima  (810)  was  highly  successful  in  that  year  on  Rome  and  suc- 
cessful in  lesser  degree  on  Osimoe,  while  pollen  of  M.  prunifolia  var. 
(838)  used  on  28  flowers  of  Ben  Davis  failed  there,  as  on  the  47 
flowers  of  Jonathan.  In  1914  the  matings  with  M.  floribunda  (821) 


408  BULLETIN  No.  275 

and  M.  baccata  maxima  (810)  were  repeated;  the  former  was  30  per- 
cent, and  the  latter  22  percent  successful.  The  1913  mating  with  M. 
prunifolia  (838)  repeated  in  1915  gave  38  fruits  from  pollination  of 
49  flowers,  or  a  success  percentage  of  77.55.  This  was  the  highest  suc- 
cess attained  in  any  cross  between  Jonathan  and  one  of  the  crab  group. 
The  seven  orchard  crosses  that  produced  fruits  in  percentages 
ranging  from  nearly  16  for  the  cross  Jonathan  X  M .  sylvestris  fasti- 
giata  bifera  (820)  to  77.5  for  the  cross  Jonathan  X  M.  prunifolia  var. 
(838)  included  389  pollinations  and  produced  150  fruits,  or  1  fruit 
for  each  2.59  flowers  pollinated. 

Oldenburg  has  been  paired  with  nine  members  of  the  crab  group 
in  thirteen  matings.  Flowers  pollinated  numbered  215  and  fruits 
matured,  62.  Ten  of  the  matings  with  6  different  species,  and  includ- 
ing 69  pollinations  which  matured  9  fruits,  were  made  in  the  green- 
house; and  three  including  146  pollinations  yielding  53  fruits  were 
made  in  orchard.  The  success  percentage  for  all  pollinations  was 
28.83,  and  the  ratio  of  fruits  to  flowers  pollinated  was  1  to  3.46.  For 
the  greenhouse  matings  the  success  percentage  was  36.30,  and  the 
ratio  1  to  2.73.  Five  of  the  greenhouse  matings,  with  38  pollinations, 
failed;  the  9  fruits  from  greenhouse  pollinations  resulted  from  five 
matings  including  31  pollinations  by  three  species,  as  follows:  pollen 
of  M.  mains  var.  (19667)  on  five  flowers  in  1914  gave  one  fruit  and 
on  11  flowers  in  1916  gave  two  fruits;  pollen  of  M.  ringo  (840)  on 
three  flowers  in  1915  gave  two  fruits  and  on  nine  flowers  in  1916  gave 
one  fruit;  and  pollen  of  M.  microcarpa  (19644)  on  three  flowers  in  1916 
gave  three  fruits.  The  failures  were,  M.  siberica  frutico  coccinea 
(19643)  on  six  flowers  in  1913;  M.  prunifolia  xanthocarpa  (839)  on 
five  flowers  in  1914;  M.  niedwietzkyana  on  four  flowers  in  1914  and 
on  19  flowers  in  1916;  and  M.  ringo  (19662)  on  four  flowers  in  1916. 
All  of  the  failures  were  on  trees  flowering  for  the  first  time  altho 
these  trees  are  on  paradise  stocks  four  and  five  yeears  old  from  the 
graft.  While  the  first  flowers  borne  usually  fail  this  is  not  always 
the  case,  as  is  illustrated  in  one  mating  by  M.  mains  var.  (19667)  in 
which,  on  a  tree  one  year  old  from  graft  on  paradise  stock,  pollination 
of  five  of  the  six  flowers  in  the  single  cluster  yielded  one  mature  fruit. 
The  test  of  Oldenburg  in  orchard  mated  with  species  of  Malus  covers 
only  three  species  and  is  not  as  extensive  as  is  desirable,  but  so  far  as 
it  goes  results  are  satisfactory;  the  percentages  of  success  are  dis- 
tinctly above  the  average  for  this  group  of  orchard  varieties  X  crab- 
like  forms. 

Rome  has  had  686  pollinations  distributed  in  ten  matings  with 
eight  different  forms  of  Malus.  Two  of  these  forms  are  under  the 
same  name,  Yellow  Siberian  Crab,  but  as  they  are  quite  distinct  the 
identity  of  each  has  been  maintained  in  the  records.  The  matings 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


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410  BULLETIN  No.  275  [June 

with  M.  prunijolia  var.  (838)  and  M.  floribunda  (821)  made  in  1914 
were  repeated  in  1915  and  the  two  matings  for  each  are  here  com- 
bined. The  fruits  matured  aggregate  303,  represent  44.16  percent  of 
the  pollinations,  and  give  a  ratio  of  one  fruit  for  each  2.26  flowers  pol- 
linated. This  is  considerably  above  the  success  percentage  of  34.83 
and  the  ratio  of  fruits  to  flowers  pollinated  of  1  to  2.87  recorded  for 
Rome  in  group  1  where  the  pollen  was  supplied  by  orchard  varieties. 
There  were  no  entire  failures.  The  lowest  success  percentage  is  found 
in  the  cross  Rome  X  M.  baccata  (806)  where  46  pollinations  gave 
four  fruits,  a  percentage  of  8.7;  the  highest  success  is  recorded  in  117 
fruits  from  200  pollinations  by  M.  prunijolia  var.  (838)  giving  58.5 
as  the  success  percentage.  All  the  Rome  pollinations  here  considered 
were  made  on  one  individual,  a  tree  about  twenty  years  old.  It  is 
not  known  whether  or  not  other  individuals  of  the  variety  possess  the 
same  fertility,  but  surely  this  one  is  a  good  breeder  and  its  per- 
formance very  gratifying. 

Seed  Production  in  Hybrid  Fruits  of  Group  2 

The  total  seeds  saved  from  the  1,101  fruits  produced  by  the  mat- 
ings  within  this  group  of  orchard  varieties  X  crab-like  forms  was  7,862 
(Table  10).  The  average  number  of  seeds  to  each  fruit  is  then  7.14, 
which  is  slightly  higher  than  the  average  of  7.06  for  the  990  fruits  of 
the  group  orchard  varieties  X  orchard  varieties.  Seed  production  of 
individual  fruits  ranged  from  0  to  17.  There  were  22  parthenocarpic 
fruits,  16  that  produced  1  seed  each,  33  that  produced  2  seeds  each, 
and  37  that  produced  3  each;  at  the  other  extreme  3  fruits  produced 
the  maximum  of  17,  4  fruits  had  16  each,  3  had  15  each,  and  6  had 
14  each.  The  highest  frequency  fell  upon  8  seeds  each  and  this  was 
represented  by  189  fruits,  or  17.17  percent  of  the  total  number;  352 
fruits,  or  31.97  percent,  ranged  above  this  highest  frequency,  and  560 
fruits,  or  50.86  percent,  produced  seeds  in  less  numbers  than  eight  or 
were  seedless. 

Of  the  35  varieties  used  as  mothers  in  this  group,  6 — namely, 
Delicious,  Early  Ripe,  Fanny,  Jefferis,  Lady,  and  Winter  Rambo — 
produced  no  fruits  and  hence  have  no  representation  in  the  seed  distri- 
bution list.  The  29  varieties  yielding  fruits  range  widely  both  in 
numbers  of  fruits  and  in  seed  distribution.  Huntsman  with  19  fruits 
leads  all  others  in  high  seed  production,  with  an  average  of  13.52 
seeds  to  each  fruit  and  a  distribution  range  from  8  as  the  minimum  for 
2  fruits  to  17  as  the  maximum  for  each  of  3  fruits.  The  maximum 
next  below  Huntsman  is  14  seeds  reached  by  4  fruits  of  Melonen. 
This  variety  is  represented  by  only  12  fruits;  its  minimum  is  5  seeds 
for  1  fruit  followed  by  one  with  6  seeds,  2  with  9  each,  1  each  with 
10  and  11,  and  2  with  13  each;  its  average  is  11.  Three  varieties  reach 
a  maximum  of  13  seeds — Domine  with  2  fruits,  Roe's  Duchess  Seed- 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  411 

ling  and  Rome  with  1  fruit  each.  Three  varieties,  each  producing 
1  fruit,  had  seeds  as  follows:  Arkansas  and  Twenty  Ounce,  8  each; 
Red  Astrachan,  4.  The  22  parthenocarpic  fruits  were  distributed 
among  6  varieties:  Ben  Davis  had  2,  Black  Ben  Davis  had  1,  Jonathan 
had  5,  Rome  had  10,  Shackleford  had  1,  and  Stayman  Winesap  had  3. 
With  regard  to  the  normal  of  10  seeds  to  each  apple,  there  are 
18  that  reached  and  9  that  exceeded  this  number;  the  aggregate  of 
fruits  having  10  seeds  each  is  120,  or  approximately  11  percent  of  all 
fruits.  The  11  varieties  that  fall  short  of  10  seeds  to  each  fruit  repre- 
sent 924,  or  83.92  percent  of  the  total  number  of  fruits.  Comparison  of 
the  behavior  of  particular  varieties  is  scarcely  possible  because  of 
diversity  in  the  parental  combinations,  seasonal  differences,  and  the 
fact  that  many  of  the  varieties  were  represented  by  very  small  num- 
bers of  fruits.  Table  10  gives  the  seed  distribution  for  all  the  95 
fruiting  combinations  grouped  according  to  varieties  serving  as 
pistillate  parents. 

Season  of  Maturity  of  Hybrid  Fruits 

The  period  during  which  hybrid  fruits  are  picked  and  described 
is  somewhat  prolonged,  extending  for  all  seasons  including  1916  from 
June  16  to  November  10,  but  varying  somewhat  in  different  seasons. 
Hybrid  fruits  developed  from  pollinations  of  orchard  varieties  by 
species  of  Malus  in  the  greenhouse  in  March  and  April  have  picking 
dates  ranging  from  June  16  for  Yellow  Transparent  to  September  28 
for  Akin ;  for  fruits  from  orchard  trees  the  range  of  picking  dates  was 
from  July  27  for  Yellow  Transparent  to  November  10  for  Ben  Davis, 
Collins,  and  Winesap. 

It  is  desirable  that,  when  picked,  the  fruits  of  summer  and  fall 
varieties  be  of  edible  rather  than  of  commercial  maturity  in  order  to 
judge  accurately  such  characters  as  color,  texture  of  flesh,  and  flavor, 
but  in  the  absence  of  cold  storage  facilities  it  has  been  impossible 
to  describe  all  fruits  when  in  the  ideal  condition.  There  have  been 
errors  in  both  directions;  in  some  cases  fruits  have  been  picked  that 
should  have  remained  on  the  trees  a  few  days  longer,  but  the  most 
frequent  mistake  has  been  in  allowing  fruits  to  reach  a  somewhat 
over-ripe  condition.  A  succession  of  hot  days  near  the  time  of  normal 
maturity  so  hastens  the  ripening  processes  that  the  number  of  fruits 
ready  for  description  on  a  given  day  may  be  in  excess  of  the  number 
that  can  be  cared  for;  those  subjected  to  delay  rapidly  deteriorate 
and  description  is  less  satisfactory.  With  the  advent  of  anticipated 
cold  storage,  this  difficulty  will  be  largely  eliminated,  for  by  arranging 
for  more  frequent  inspection  it  appears  possible  that  all  fruits  may 
be  picked  at  just  the  proper  time  for  most  accurate  record  and  held 
at  a  low  temperature  until  description  can  be  made,  thus  eliminating 


412  BULLETIN  No.  275  [June, 

the  haste  that  is  now  often  necessary,  and  insuring  a  more  satisfactory 
record. 

Losses  of  Seeds  Between  Extraction  and  Planting 

Under  the  system  practiced  in  handling  the  seeds  of  hybrid  fruits, 
as  explained  in  connection  with  Group  1,  seeds  of  fruits  from  green- 
house pollinations  have  been  held  before  planting  for  periods  varying 
between  69  and  173  days,  and  those  from  fruits  on  orchard  trees  from 
26  to  113  days.  The  aggregate  of  seeds  saved  from  the  1,101  fruits  of 
this  group  was  7,862,  or  an  average  of  7.14  seeds  to  each  fruit.  The 
number  of  seeds  planted  was  7,512;  this  shows  a  loss  of  350  seeds  in 
the  interval  of  dry  storage,  or  4.45  percent  of  the  total  seeds  saved. 
This  percentage  of  loss  is  appreciably  smaller  than  that  recorded  for 
Group  1,  which  was  nearly  8  percent,  and  appears  to  be  due  to  the 
fact  that  in  Group  2  there  were  noticeably  less  .numbers  of  ovules 
developing  what  appeared  to  be  good  seeds  but  which  were  without 
embryos. 

Percentage  of  Germination  Higher  in  Group  2  Than  in  Group  1 

The  percentage  of  germination  recorded  for  the  seeds  in  Group  1 
was  62.22.  For  Group  2  this  percentage  is  distinctly  higher.  The 
number  of  seeds  planted  was  7,512;  of  these  5,408  are  recorded  as 
having  germinated.  This  is  71.99  percent  of  the  number  of  seeds 
planted  and,  for  apple  seeds  artificially  hybridized,  may  be  regarded 
as  a  fairly  satisfactory  percentage.  As  was  the  case  in  Group  1, 
there  is  wide  variation  between  the  varieties  in  the  matter  of  ger- 
mination. There  were  three  matings  in  which  all  seeds  failed  to  ger- 
minate; Arkansas  X  Yellow  Siberian  Crab  (857),  in  which  50  flowers 
pollinated  in  orchard  in  1914  yielded  1  fruit  from  which  4  seeds  were 
planted;  Stayman  Winesap  X  M.  niedwietzkyana  (834),  in  which  6 
flowers  pollinated  in  the  greenhouse  in  1916  yielded  1  fruit  from  which 
1  seed  was  planted;  and  Yellow  Transparent  X  M.  scheideckeri 
(19646),  in  which  3  flowers  pollinated  in  the  greenhouse  in  1915 
yielded  2  fruits  from  which  13  seeds  were  planted.  Thus  these  three 
matings  involve  59  pollinations  and  4  fruits  with  18  seeds.  Arkansas 
has  proved  a  very  unsatisfactory  mother,  and  efforts  thus  far  made 
to  hybridize  it  have  been  unsuccessful;  50  pollinations  by  M. 
prunifolia  var.  (856)  failed  entirely,  and  50  pollinations  by  Yellow 
Siberian  Crab  developed  one  fruit  as  stated  above;  this  fruit  had  8 
seeds,  4  of  which  were  planted,  but  none  germinated;  in  addition  273 
pollinations  divided  among  4  orchard  varieties  yielded  no  fruits.  The 
one  tree  used  is  in  orchard,  more  than  twenty  years  old,  and  with  a 
record  of  abundant  bloom  and  very  few  fruits.  Stayman  Winesap  has 
no  better  record  than  Arkansas;  99  pollinations  have  been  made  by 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  413 

8  different  forms  of  Malus;  6  of  the  attempts  gave  no  fruits,  one  gave 
3  seedless  fruits,  and  the  remaining  one  is  that  referred  to  above. 

These  pollinations  were  all  on  potted  dwarf  trees  in  the  green- 
house and  it  is  probable  that  failure  should  be  ascribed  to  the  youth 
of  the  trees  and  the  utilization  of  the  first  flowers  borne.  Yellow 
Transparent  has  scored  more  failures  than  successes;  four  of  thirteen 
matings  with  eleven  different  forms  of  Malus  gave  degrees  of  success 
as  follows:  44  flowers  pollinated  in  orchard  by  M.  prunifolia  (838) 
yielded  2  fruits  containing  18  seeds,  8  of  which  germinated;  3  flowers 
pollinated  in  the  greenhouse  by  M.  scheideckeri  (19646)  gave  2  fruits 
with  13  seeds,  none  of  which  germinated  (this  is  the  mating  previously 
referred  to.  Pollination  of  10  flowers  in  the  greenhouse  by  M.  nied- 
wietzkyana  gave  5  fruits  with  30  seeds,  22  of  which,  or  73.33  percent, 
germinated;  11  flowers,  also  in  the  greenhouse,  pollinated  by  M.  ringo 
(840)  gave  1  fruit  and  6  seeds,  3  of  which  germinated.  The  nine 
matings  that  failed  entirely  were:  in  orchard,  48  flowers  by  M.  baccata 
(807),  40  flowers  by  M.  toringo  (19664),  and  19  flowers  by  M. 
baccata  maxima  (810) ;  in  greenhouse,  4  flowers  in  1914  by  M.  micro- 
carpa  (19644),  5  flowers  by.M.  coronaria  (818),  4  flowers  by  M. 
ioensis  ft.pl.  (826),  10  flowers  by  M.  siberica  frutico  coccinea  (19643), 

5  flowers  in  1916  by  M.  microcarpa  (19644)  and  13  flowers  by  M. 
ringo  (19662). 

Summarizing  the  attempts  to  hybridize  Yellow  Transparent  with 
forms  of  Malus  it  appears  that  216  pollinations  were  made,  10  of 
which,  or  4.63  percent,  were  successful;  that  is,  this  number  produced 
fruits.  The  ratio,  1  fruit  for  21.6  flowers,  is  low.  These  fruits  con- 
tained 68  seeds,  and  of  the  67  which  were  planted  33,  or  49.25  per- 
cent, germinated.  Of  the  33  seedlings,  31  are  now  living,  6  of  them  in 
orchard  now  six  years  old,  and  the  balance  in  the  nursery.  While  the 
record  of  Yellow  Transparent  is  low  as  to  fruit  production  the 
performance  of  the  seeds  is  fairly  creditable.  For  five  of  the  matings 
all  seeds  produced  are  recorded  as  having  germinated,  but  in  all  of 
these  the  numbers  of  seeds  are  small.  Four  of  the  matings  had  but 
1  fruit  each  and  the  other  3  fruits;  they  are  as  follows:  Ben  Davis  X 
M.  baccata  maxima  (810)  4  seeds  from  1  fruit,  Domine  X  M.  baccata 
var.  (806)  37  seeds  from  3  fruits,  Tolman  X  M.  atrosanguinea  (804) 

6  seeds  from  1  fruit,  Tolman  X  M.  sylvestris  jastigiata  (820)  5  seeds 
from  1  fruit,  and  Twenty  Ounce  X  M.  ringo  (19662)  8  seeds  from  1 
fruit;  this  last  was  from  greenhouse  pollinations,  the  others  were  from 
pollinations  in  orchard. 

Naturally  the  varieties  represented  by  the  largest  numbers  of 
seeds  give  the  most  satisfactory  records  because  the  strength  of  num- 
bers adds  to  the  reliability  of  percentages  arid  supplies  a  better  basis 
from  which  to  estimate  performance;  thus  for  Akin  29  seeds,  or  87.87 
percent  of  the  33  planted,  germinated,  and  for  Collins  3  seeds,  or 


414  BULLETIN  No.  275  tJime, 

18.75  percent  of  the  16  planted,  germinated,  which  are  the  extremes 
of  germination.  Percentages  in  this  group  are  not  such  satisfactory 
indices  of  the  possibilities  of  the  varieties  as  are  the  percentages  for 
Rome,  Grimes,  Jonathan,  or  Tolman.  These  4  varieties  have  records 
as  follows:  Rome  from  ten  matings  with  7  different  crab-forms  gave 
303  fruits;  from  these  fruits  2,115  seeds  were  planted  and  1,721,  or 
81.34  percent,  germinated;  Grimes  gave  only  12.25  percent  of  success 
in  fruit  production,  but  from  the  87  fruits  from  matings  with  16  forms 
of  Malus,  722  seeds  were  planted,  608,  or  84.21  percent,  of  which  ger- 
minated. Jonathan  from  646  flowers  pollinated  by  14  different  crab- 
forms  gave  151  fruits;  from  these  835  seeds  were  planted  and  598 
germinated;  this  is  71.61  percent  of  successful  germination.  Tolman 
was  mated  with  ten  different  forms  and  nine  of  them  produced  102 
fruits;  of  the  796  seeds  planted  563,  or  70.90  percent,  germinated. 

Hybrid  Seedlings  Now  Living 

When  the  living  hybrid  seedlings  were  enumerated  late  in  the  fall 
of  1916,  those  originating  from  pollinations  in  Group  2  numbered 
4,001,  ranging 'in  age  from  one  to  five  .years.  The  number  of  seeds 
recorded  as  having  germinated  was  4,848,  so  that  the  number  of  seed- 
lings lost  up  to  the  time  of  the  last  enumeration  was  847,  or  17.47 
percent.  This  represents  the  loss  percentage  of  the  aggregate  of  seed- 
lings. If  division  is  made  into  annual  groups,  the  loss  percentages 
vary  widely,  and  naturally  the  older  groups  exhibit  the  highest  per- 
centages of  loss  because  they  have  had  a  longer  time  in  which  to 
eliminate  weak  seedlings,  and  also  because  the  seedlings  have  been 
subjected  for  a  longer  period  to  the  ravages  of  insects  and  diseases 
and  all  the  accidents  that  commonly  befall  young  seedlings.  Since  the 
enumeration  of  seedlings  in  the  fall,  the  seeds  from  fruits  derived  from 
pollinations  in  1916  have  been  planted,  the  record  of  germination  has 
been  obtained,  the  living  seedlings  have  been  planted  in  nursery,  and 
the  record  of  the  group,  so  far  as  it  goes,  may  be  included  with  the 
older  groups  of  seedlings.  The  aggregate  of  seeds  germinated  for  all 
seasons,  1911  to  1916,  is  5,408  and  the  number  of  seedlings  now  living 
is  4,533,  which  represents  83.82  percent  of  the  germinations.  The 
relation  of  the  year  groups  to  each  other  is  shown  in  Table  11.  The 
four  older  groups  of  trees  are  now  in  the  orchard,  the  lot  from  pollina- 
tions in  1914  having  been  planted  in  April  of  the  present  year;  the 
two  younger  lots  are  in  the  nursery. 

Comparing  Table  11  with  the  similar  one  for  Group  1  (Table  3), 
the  differences  appearing  are  not  such  as  to  suggest  any  striking  differ- 
ences in  persistence  of  the  seedlings  of  the  two  groups.  Group  2  had 
nearly  35  percent  more  seeds  and  more  than  53  percent  more  trees  than 
had  Group  1 ;  the  distribution  over  the  different  years  is  less  uniform, 
and  as  for  percentages  of  seedlings  living,  the  one-,  three-,  and  five- 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


415 


year-old  trees  have  higher  percentages  in  Group  1  than  in  Group  2, 
while  for  the  two-  and  four-year-old  trees  the  higher  percentages  are 
those  of  Group  2.  Percentages  of  the  aggregate  are  73.67  for  Group  1 
and  83.82  percent  for  Group  2. 

Individual  Records  in  Group  2 

As  illustrations  of  the  behavior  of  orchard  varieties  when  pollin- 
ated by  crab-like  forms  of  Malus,  detailed  record  of  certain  of  the 

TABLE  11. — NUMERICAL  RELATION  OP  LIVING  SEEDLINGS  TO  SEEDS  GERMINATED 

IN  GROUP  2,  ORCHARD  VARIETIES  X  CRAB-LIKE  FORMS  OF  MALUS,  WITH 

PERCENTAGES  AND  AGES  OF  TREES 


Year 

Seeds 
germi- 
nated 

Trees  living 

Age  of 
trees, 
yrs. 

Number 

Percentage 

1911.. 

54 
351 
161 
2  208 
2  074 
560 

35 

227 
115 
1  776 
1  848 
532 

64.81 
64.67 
71.42 
80.43 
89.10 
95.00 

5 
4 
3 
2 
1 

X 

1912  

1913  

1914  . 

1915  

1916  

Total  

5  408 

4  533 

83.82 

varieties  may  be  given  in  the  same  manner  as  for  certain  individuals  of 
Group  1,  and  as  in  that  group,  Oldenburg  may  be  considered  first. 
Flowers  of  Oldenburg  were  pollinated  by  9  different  members  of  the 
crab  group  in  thirteen  matings,  five  of  which  failed  to  produce  fruits. 
The  aggregate  of  flowers  pollinated  was  215,  of  which  number  62,  or 
28.83  percent,  yielded  mature  fruits.  Only  three  of  the  thirteen 
matings  wrere  on  trees  in  orchard.  These  included  146,  or  67.9  percent, 
of  flowers  pollinated  and  produced  53,  or  85.48  percent,  of  the  total 
number  of  fruits.  Of  the  ten  matings  with  6  Malus  forms,  five,  with 
38  pollinations,  failed  to  produce  fruits,  and  five,  with  31  pollinations, 
produced  9  fruits  (Table  12).  Because  of  difference  in  numbers  of 
pollinations  and  the  fact  that  the  tabulation  for  Oldenburg  in  Group  1 
involved  only  orchard  pollinations,  while  the  tabulation  in  Group  2 
includes  a  large  proportion  of  inside  matings,  the  two  tabulations  are 
not  readily  compared,  but  it  may  be  pointed  out  that  for  Group  1  the 
ratio  of  fruits  to  flowers  pollinated  is  1  to  2.44,  and  in  Group  2  this 
ratio  is  1  to  3.46,  or,  to  state  the  relation  in  percentages,  pollinations 
were  40.85  percent  successful  in  Group  1,  and  28.83  percent  successful 
in  Group  2.  In  the  matter  of  germination  the  advantage  lies  the  other 
way.  Of  the  seeds  planted  from  pollinations  in  Group  1,  56.75  percent 
germinated,  and  in  Group  2  this  percentage  was  61.38.  The  percentage 
of  seedlings  persisting  in  Group  1  was  82.7;  in  Group  2,  89.2.  This 
difference  is  small  and  when  the  age  differences  are  considered  it  may 


416 


BULLETIN  No.  275 


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418  BULLETIN  No.  275  [June, 

be  ignored.  The  rate  of  seed  production  is  somewhat  better  for  pollin- 
ations by  orchard  varieties  than  for  those  by  crab-like  forms  of  Malus. 
For  Group  1  there  were  saved  6.62  seeds  for  each  fruit,  while  for  Group 
2  there  were  only  5.61  seeds  for  each  fruit.  Between  extraction  and 
planting  95  seeds  were  lost,  or  about  65  percent  in  Group  1,  while  in 
Group  2  only  1  of  the  348  seeds  was  lost,  or  little  more  than  %  of 
1  percent. 

As  a  second  illustration  of  the  behavior  of  orchard  varieties  pol- 
linated by  crab-like  forms,  Rome,  which  has  been  considered  in  its 
relation  to  orchard  varieties  as  pollenizers,  may  be  used.  This  variety, 
as  it  appears  in  Group  2,  was  pollinated  by  8  different  forms  of  Malus 
in  ten  distinct  matings.  Two  of  the  forms  appear  under  the  same 
name  Yellow  Siberian  Crab,  but  one  has  in  addition  the  number  857. 
The  one  wdthout  the  number  was  a  large  spreading  tree  twenty  or  more 
years  old ;  the  one  carrying  the  number  857  was  a  small  tree  six  years 
of  age  at  the  time  its  pollen  was  used,  extremely  upright  in  habit,  and 
with  fruit  larger  but  of  the  same  yellow  color  as  that  produced  by  the 
large  tree.  The  two  forms  came  from  widely  different  sources  and  are 
held  to  be  varietally  distinct. 

Percentages  of  success  range  from  8.7  for  the  cross  Rome  X  M. 
baccata  (806),  in  which  46  flowers  pollinated  gave  4  fruits,  to  61  for 
the  cross  Rome  X  M.  prunijolia  (838),  in  which  100  flowers  pollin- 
ated gave  61  fruits.  For  all  the  crosses  the  success  percentage  is  44.16. 
This  is  distinctly  higher  than  the  percentage  (34.33)  found  for  the 
group  of  Rome  crosses  with  orchard  varieties  (Table  13). 

Pollinations  in  this  group  of  Rome  crosses  aggregate  686  and  the 
fruits  number  303.  This  is  a  ratio  of  1  fruit  for  each  2.26  flowers 
pollinated,  which  indicates  a  somewhat  better  performance  than  is 
recorded  for  the  group  of  crosses,  Rome  X  orchard  varieties,  in  which 
the  ratio  of  fruits  to  flowers  pollinated  is  1  to  2.87.  The  two  groups  are 
alike  in  that  all  crosses  in  both  are  on  trees  in  orchard  and  that  no 
entire  failure  appears  in  either.  In  the  two  groups,  percentages  of 
success  range  somewhat  widely  but  are  reasonably  satisfactory  in 
both.  The  ratio  of  seeds  saved  to  fruits  is  6.72  seeds  to  each  fruit  in 
Group  1,  and  7.2  seeds  to  each  fruit  in  Group  2.  Loss  of  seeds 
between  extraction  and  planting  is  much  higher  for  Group  1  than  for 
Group  2,  amounting  to  10  percent  for  the  former  and  approximately  3 
percent  for  the  latter.  For  the  pollinations  by  orchard  varieties,  seed 
germination  reaches  70.54  percent  and  for  pollinations  by  crab-like 
forms  of  Malus,  81.33  percent.  So,  too,  in  persistence  of  seedlings  the 
higher  percentage  is  found  in  Group  2,  and  the  difference  is  consider- 
able (68.81  percent  for  Group  1  and  85.35  percent  for  Group  2),  but 
some  allowance  must  be  made  here  for  the  fact  that  a  larger  proportion 
of  the  seedlings  of  Group  2  fall  into  the  very  young  groups. 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  419 

No  variety  used  has  a  higher  breeding  record  than  has  Rome;  it 
accepts  the  pollen  of  orchard  varieties  and,  with  equal  facility,  so  far 
as  tested,  the  pollen  of  quite  diverse  forms  of  the  crab-group.  The 
proportion  of  fruits  produced  is  considerably  above  the  average,  the 
seeds  are  reasonably  viable,  of  average  abundance,  and  the  seedlings 
possess  good  vitality.  As  shown  in  the  tabulations,  the  12  combinations 
with  orchard  varieties  and  the  8  combinations  with  crab-like  forms  are 
represented  by  more  than  2,000  living  seedlings,  a  large  majority  of 
which  are  expected  to  reach  fruiting  maturity.  It  is  regarded  as  an 
interesting  group  because  a  single  individual  is  the  mother  of  all  and 
the  pollen  plants  contribute  extremely  diverse  characters  of  flower, 
foliage,  and  fruit. 

GROUP  3 :    CRAB-LIKE  FORMS  OF  MALUS  X 
ORCHARD  VARIETIES 

Forms  of  Mains  Used  as  Pistillate  Parents 

Hybrids  of  this  group  are  the  reciprocals  of  hybrids  of  Group  2. 
In  Group  3  the  pistillate  parent  was  in  all  cases  one  of  the  crab-like 
forms  of  Malus,  and  the  pollen  the  product  of  a  recognized  orchard 
variety.  The  aggregate  of  matings  within  the  group  was  320  and  the 
number  of  distinct  parental  combinations,  245.  There  were  used  as 
mothers  44  different  forms  of  Malus,  and  the  pollen  employed  came 
from  29  different  orchard  varieties.  Matings  were  distributed  over  the 
years  1909  and  1911  to  1916,  the  larger  numbers  in  the  later  years. 
In  1909  there  were  only  3  matings  in  this  group,  in  1911  only  4. 
Plants  propagated  in  1907  and  1908  commenced  flowering  in  1912,  and 
for  that  year  there  were  33  matings.  In  1913  there  were  26,  and  in 
1914  the  number  rose  to  88,  then  dropped  to  35  in  1915  because  in  that 
year  most  trees  failed  to  flower.  For  1916,  the  last  year  for  which 
record  is  given,  the  number  of  matings  reached  132.  The  diversity  of 
the  Malus  forms  used  as  pistillate  parents  in  this  group  is  perhaps 
most  readily  shown  by  bringing  the  names  together  as  in  Table  14. 
With  each  named  form  is  included  the  number  of  matings  in  which  it 
has  been  used,  the  number  of  varieties  of  pollen  used  to  pollinate  its 
flowers,  the  number  of  flowers  pollinated,  and  the  number  of  fruits 
resulting  from  the  pollinations  made. 

The  forms  included  in  Table  14  exhibit  wide  diversity  in  their 
characteristics  but  each  has  its  distinguishing  marks;  the  six  forms 
of  M.  baccata  all  clearly  belong  to  that  species,  but  each  has  at 
least  one  character  that  readily  distinguishes  it  from  any  of  the  others. 
In  the  same  way  the  five  forms  of  M.  prunifolia,  while  evidently 
properly  associated  in  specific  rank,  are  distinguished  from  each  other 
without  difficulty.  The  various  forms  have  been  utilized  quite 
unequally,  chiefly  because  some  have  been  more  often  and  more  abun- 


420 


BULLETIN  No.  275 


TABLE  14. — FORMS  OF  MALUS  USED  AS  PISTILLATE  PARENTS  IN  GROUP  3,  CRAB-LIKE 
FORMS  OF  MALUS  X  ORCHARD  VARIETIES 


Species  or  variety 

Number 
of 
matings 

Number 
of  par- 
ental 
combi- 
nations 

Flowers 
polli- 
nated 

Fruits 
matured 

1  M.  arnoldiana  (802)  

7 

5 

1  895 

108 

2  M  .  atrosanguinea  (804)  

8 

7 

604 

57 

3  M.  baccata,  red  fruit  (806)    .  .  . 

5 

4 

993 

201 

4  M  .  baccata,  red  fruit,  late  ....  (807)  

6 

5 

700 

253 

5  M  .  baccala  var  (808)  

1 

1 

135 

0 

6  M.  baccata  maxima  (810)  

8 

5 

959 

316 

7  M  .  baccata  oblonga  (811)  

5 

5 

77 

70 

8  M.  baccata  var.  sieboldi  (814)  

2 

2 

376 

100 

9  M.  coronaria  (818)  

5 

5 

54 

5 

10  M.  dioica  (819)  

7 

5 

220 

14 

11  M  .  sylvestris  fastigiata  bifera.  .  (820)  

15 

11 

362 

121 

12  M.  floribunda  (821)  

14 

11 

2  220 

138 

13  M.  sp(?)  Fluke  Apple  (822)  

5 

4 

43 

5 

14  M.  halliana  (823)  

2 

2 

114 

0 

15  M.  sp(?)  Hyslop  Crab  (824)  

3 

3 

153 

57 

16  M.  ioensis  (825)  

2 

2 

185 

65 

17  M.  ioensisfl.  pi  (826)  

1 

1 

10 

0 

18  M.  malus  var  (830)  

2 

2 

94 

1 

19  M.  malus  fl.  pi  (833)  

1 

1 

226 

10 

20  M.  niedwietzkyana  (834)  

9 

7 

290 

1 

21  M.  prunifolia  macrocarpa.  .  .  .  (837)  

6 

6 

252 

8 

22  M.  prunifolia  var  (838)  

15 

13 

770 

421 

23  M  .  prunifolia  xanthocarpa.  .  .  .  (839)  

3 

2 

91 

4 

24  M.  ringo  (840  &  19662)  

27 

11 

922 

188 

25  M.  fusca  (841)  

1 

1 

117 

11 

26  M.  sargenti.  (843)  

11 

8 

235 

101 

27  M.  soulardi  (846)  

17 

11 

310 

9 

28  M.  spectabilis—459  (849)  

8 

8 

58 

11 

29  M.  toringo  (851)  

5 

5 

121 

56 

30  M.  toringo  (853)  

2 

2 

49 

26 

31  M.  ringo  sublobata..   (854  &  19689)  

19 

14 

1  825 

803 

32  M.  prunifolia  var.  5004  (856)  

3 

3 

90 

38 

33  M  .  Yellow  Siberian  Crab  (857)  

7 

5 

294 

46 

34  M.  siberica  frulico  coccinea.  (19643)  

12 

8 

513 

124 

35  M  .  microcarpa  (19644)  

8 

8 

609 

229 

36  M.  scheideckeri  (19646)  .... 

16 

12 

827 

202 

37  M  .  prunifolia  var  (19651)  

6 

5 

91 

16 

38  M.  toringo  (852  &  19664)  

15 

11 

517 

130 

39  M.  malus  var  (19667)  

15 

9 

607 

177 

40  M  .  malus  pendula  .    (832  &  19688)  

2 

2 

22 

0 

41  M.  Whitney  Crab  

1 

1 

50 

26 

42  M.  Yellow  Siberian  Crab  

9 

8 

412 

1 

43  M  .  Florence  Crab  

2 

2 

90 

41 

44  M.  General  Grant  Crab  

2 

2 

94 

35 

Total.  . 

320 

245 

19  676 

4  225 

dantly  available  than  others;  some  have  flowered  regularly  since  the 
first  year  of  flower  production,  while  others  appear  to  have  the  habit  of 
biennial  flowering.  Some  exist  only  as  small  potted  trees  that  are 
forced  under  glass  and  produce  but  few  flowers. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  421 

Four  of  the  forms  on  which  pollinations  were  made  and  which 
yielded  no  fruits  were  M.  baccata  (808),  M.  halliana  (823),  M.  ioen- 
sis  fl.pl.  (826),  and  M.  mains  pendula  (832).  On  an  eight-year-old 
tree  of  M.  baccata  (808),  flowering  sparingly  for  the  second  time,  135 
flowers  were  supplied  with  Jonathan  pollen  in  1915;  no  fruits  resulted 
altho  a  few  fruits  developed  from  flowers  open  to  insect  pollination. 
Two  attempts  were  made  on  M.  halliana  (823) ;  the  first  in  1915  on  a 
potted  tree  flowering  for  the  first  time  in  the  greenhouse  and  8  flowers 
wrere  pollinated  with  pollen  of  Yellow  Transparent. 

In  1916  a  tree  in  orchard  flowered  for  the  first  time  and  106 
flowers  were  pollinated  with  Oldenburg  pollen;  in  this  case  no  fruits 
formed  on  the  tree.  The  attempt  on  M.  ioensis  fl.pl.  (826)  was  without 
expectancy  of  success  in  view  of  the  extreme  fulness  of  the  flowers. 
The  tree  used  was  on  a  dwarf  stock  in  pot  in  the  greenhouse ;  10  flowers 
were  emasculated  and  pollinated  with  Yellow  Transparent  pollen,  but 
neither  the  protected  flowers  nor  those  left  open  produced  any  fruits. 
Multiplication  of  parts  in  flowers  of  this  crab  is  carried  to  a  greater 
extent  than  in  flowers  of  any  other  form  examined;  petals  vary  in 
number  from  18  to  28,  stamens  from  25  to  34,  and  styles  from  9  to  11. 
The  remaining  form  that  failed  in  fruit  production,  M.  mains  pendula 
(832),  was  also  on  dwarf  stock  in  the  greenhouse;  in  this  case  8 
flowers  were  pollinated  by  Akin  pollen  and  14  by  Oldenburg  pollen. 
Three  other  forms  narrowly  missed  entire  failure;  Yellow  Siberian 
Crab  from  nine  matings  with  8  orchard  varieties  gave  only  1  fruit  from 
412  pollinations;  M.  mains  var.  (830)  from  two  matings  with  2 
varieties  gave  1  fruit  from  94  pollinations,  and  M.  niedwietzkyana 
from  nine  matings  with  7  varieties  gave  1  fruit  from  290  pollinations. 
From  these  low  degrees  of  success  there  were  all  grades  up  to  70  fruits 
from  77  pollinations,  or  90.9  percent  for  the  aggregate  of  five  matings 
of  M.  baccata  oblonga  (811)  with  five  different  pollen  plants.  Indiv- 
idual matings  to  the  number  of  eight  were  100  percent  successful,  but 
these  involved  small  numbers  of  pollinations;  they  were  as  follows: 
in  the  greenhouse,  M.  baccata  oblonga  (811)  X  Oldenburg,  3  pollina- 
tions; M.  sylvestris  fastigiata  bifera  (820)  X  Oldenburg,  5  pollin- 
ations; M.  toringo  (19664)  dwarf  form  X  Grimes,  10  pollin- 
ations; M.  mains  var.  (19667)  X  Grimes,  7  pollinations;  and  by 
Yellow  Transparent,  16  pollinations;  in  the  orchard,  M.  prunifolia 
(838)  X  Osimoe,  11  pollinations,  and  by  Ben  Davis,  33  pollinations. 
Considering  the  group  as  a  whole  the  aggregate  of  flowers  pollinated 
was  18,676  and  the  number  of  fruits  matured,  4,225.  The  fruits  repre- 
sent 22.62  percent  of  the  flowers  pollinated,  and  this  may  be  compared 
with  15.83  percent  as  similarly  determined  for  Group  2,  and  12.9 
percent  for  Group  1.  The  ratios  of  matured  fruits  to  flowers  pollinated 
in  the  three  groups,  are  as  follows: 


422  BULLETIN  No.  275  [June, 

Group   1 1  to  7.74 

Group  2 1  to  6.31 

Group  3 1   to  4.42 

Ratios  for  Groups  2  and  3,  in  which  crab  forms  serve  as  pistillate 
parents  in  one  and  as  pollen  parents  in  the  other,  ore  distinctly  higher 
than  the  ratio  for  the  group  in  which  both  parents  in  all  matings  were 
orchard  varieties,  and  the  ratio  for  Group  3  is  decidedly  better  than 
that  for  Group  2.  This  apparently  bears  out  the  statement  made  on  a 
preceding  page  that  pollen  of  orchard  varieties  appears  to  be  more 
acceptable  to  stigmas  of  flowers  of  crab-like  forms  than  is  the  pollen  of 
crab-like  forms  to  stigmas  of  flowers  of  orchard  varieties. 

As  already  stated,  apple  pollinations  in  the  greenhouse  began  in 
1913;  previous  to  this— that  is,  in  the  years  1909,  1911,  and  1912, 
there  had  been  made  within  Group  3  forty  matings  with  1,109  pollin- 
ations and  yielding  427  fruits  on  trees  in  orchard.  For  the  last  four 
years  the  matings  in  this  group  under  glass  have  numbered  201, 
involving  pollination  of  3,889  flowers,  and  yielding  1,040  fruits;  for  the 
same  period  the  matings  in  orchard  numbered  79,  and  included  13,678 
flowers  from  which  2,758  fruits  matured.  Thus  while  the  number  of 
inside  matings  is  considerably  larger  than  the  number  in  orchard,  the 
greater  numbers  of  flowers  were  pollinated  in  outside  matings  on 
orchard  trees.  For  the  greenhouse  the  average  number  of  flowers  in 
each  mating  was  19.34,  while  for  the  orchard  trees  the  average  was 
127.64.  Only  small  trees  producing  small  numbers  of  flowers  were 
available  in  the  greenhouse,  while  usually  the  orchard  trees  flowered 
abundantly.  The  ratio  of  fruits  to  flowers  is  higher  for  pollinations 
made  in  the  greenhouse  than  for  those  made  in  orchard.  In  the  green- 
house 3.73  flowers  were  pollinated  for  each  fruit  produced,  and  pollin- 
ation of  4.68  flowers  was  required  for  each  fruit  produced  in  orchard. 
Matings  that  failed  in  fruit  production  aggregate  101  or  31.56  percent 
of  the  total  made,  and  they  include  3,185,  or  17.05  percent,  of  the 
flowers  pollinated. 

As  between  greenhouse  and  orchard,  74  of  the  failures  involving 
821  flowers  pollinated  are  recorded  as  occurring  in  the  greenhouse  and 
27  with  2,364  flowers  pollinated  on  trees  in  orchard.  In  a  considerable 
number  of  cases  failure  was  anticipated  or  predicted  as  the  result  of 
circumstances  attending  or  observations  made  at  the  time  of  pollina- 
tion. In  some  instances  pollen  was  deliberately  applied  to  immature 
stigmas,  while  in  other  instances  periods  of  four  to  six  days  were 
allowed  to  intervene  between  emasculation  and  pollination  in  an 
attempt  to  ascertain  the  range  of  receptive  maturity  and  the  possibility 
of  effecting  fertilization  thru  immature  stigmas.  This  problem  is  an 
important  one,  but  properly  has  no  place  in  the  breeding  project  as 
now  carried  on;  it  should  be  taken  up  as  a  distinct  unit  for  more  ex- 
tended work  than  is  possible  in  connection  with  a  predetermined  pol- 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  423 

lination  schedule.  Injecting  it  into  the  line  of  effort  now  pursued  only 
serves  to  increase  the  number  of  failures  that  must  form  part  of  the 
record  of  the  project.  It  does,  however,  develop  a  better  understanding 
of  the  extent  of  the  investigation  necessary  for  the  establishment  of  a 
dependable  basis  for  definite  conclusions  regarding  this  matter  of 
receptive  maturity,  which,  tho  apparently  simple,  is  in  reality 
extremely  complex,  involving  factors  of  age,  environment,  physiologi- 
cal functions,  ancestry,  and  in  short  all  agencies  affecting  plant 
activities. 

Multiplication  of  floral  organs  is  accepted  as  the  cause  of  failure 
with  M.  ioensis  fl.pl.  (826)  and  may  be  the  cause  of  low  percentage  of 
success  with  M .  mains  fl.pl.  (833) ;  in  this  form  doubling  is  not  so 
extreme  as  in  M .  ioensis  fl.pl.  (826)  and  the  plant  is  not  wholly  sterile. 
M.  spectabilis  (849)  is  another  form  that  because  of  multiplied  parts 
may  be  classed  with  the  two  previously  mentioned,  but  like  M .  mains 
fl.pl.  (833),  it  is  not  entirely  sterile.  Extreme  differences  between  the 
forms  mated — in  other  words,  violence  of  the  cross,  may  account  for 
failure  of  several  matings  of  M.  niedwietzkyana  and  possibly  this 
same  reason  can  be  assigned  for  ill  success  with  M.  soulardi  (846)  and 
one  of  the  two  varieties  of  Yellow  Siberian  Crab.  M.  niedwietz- 
kyana was  mated  with  Stayman  Winesap,  Delicious,  Oldenburg, 
Fanny,  Oliver,  Yellow  Transparent,  and  Jonathan,  in  all  290  pollin- 
ations, but  only  one  of  18  flowers  pollinated  with  Yellow  Transparent 
developed  a  fruit.  M.  soulardi  was  mated  seventeen  times  with  11 
varieties  and  310  as  the  total  of  pollinations;  eleven  matings  with  231 
pollinations  failed  entirely,  four  with  an  aggregate  of  24  pollinations, 
gave  1  fruit  each,  one  gave  2  fruits  from  49  flowers,  and  another  3 
fruits  from  6  flowers.  This  record  shows  that  M.  soulardi  does  not 
hybridize  readily,  and  gives  sufficient  reason  for  the  impression  that 
this  form  is  at  least  unsatisfactory  as  a  mother  plant.  Yellow  Siberian 
Crab,  with  412  pollinations,  in  nine  matings  with  8  varieties  yielded 
only  1  fruit  from  48  pollinations  by  Domine.  The  varieties  with 
which  entire  failure  resulted  were  Oldenburg,  Twenty  Ounce,  Tolman, 
Yellow  Transparent,  Jonathan,  Osimoe,  and  Fanny.  Yellow  Siberian 
Crab  has  an  unsatisfactory  record  that  may  be  due  to  a  general  incom- 
patibility between  this  variety  and  those  with  which  it  was  mated,  but 
so  far  as  is  indicated  by  visible  characters  the  crosses  attempted  are 
no  more  violent  than  were  the  fifteen  matings  between  M.  mains  var. 
(19667)  and  the  same  and  other  like  varieties,  all  of  which  were  in 
some  degree  successful;  or  the  fifteen  matings  of  M.  prunifolia  (838) 
with  similar  varieties,  fourteen  of  which  were  more  or  less  successful. 
Other  forms  of  Malus  record  some  failures  but  only  in  the  three  men- 
tioned were  they  so  nearly  complete. 


424 


BULLETIN  No.  275 


[June, 


Varieties  Used  as  Pollen  Parents  in  Group  3 

The  orchard  varieties  used  to  supply  pollen  for  the  matings 
of  Group  3,  number  29,  in  great  part  were  the  same  as  those 
used  as  pistillate  parents  in  Group  2.  Twenty-five  of  them  were  used 
in  both  groups,  4  were  used  in  Group  3,  but  not  in  Group  2,  and  10 
were  used  in  Group  2  that  do  not  appear  in  Group  3.  The  varieties 
used  are  arranged  in  alphabetical  order  in  Table  15.  The  number  of 

TABLE  15. — VARIETIES  SUPPLYING  POLLEN  FOR  MATINGS  IN  GROUP  3,   CRAB-LIKE 
FORMS  OF  MALUS  X  ORCHARD  VARIETIES 


Variety 


Number 

of 
matings 


Number 

of  forms 

on  which 

used 


Flowers 
pollinated 


Fruits 
matured 


1  Akin 9 

2  Arkansas 4 

3  Beach 2 

4  Ben  Davis 55 

5  Collins 7 

6  Delicious 12 

7  Domine 29 

8  Fameuse 6 

9  Fanny 16 

10  Grimes 32 

11  Isham 2 

12  Jonathan 26 

13  Lady 5 

14  Longfield 1 

15  Maiden  Blush. 1 

16  Oldenburg 52 

17  Oliver 11 

18  Osimoe 5 

19  Red  Astrachan 3 

20  Rome 3 

21  Shackleford 6 

22  Shockley 2 

23  Stayman  Winesap 19 

24  Summer  Pound  Royal 1 

25  Tolman 2 

26  Twenty  Ounce 3 

27  Winesap 5 

28  Winter  Rambo 10 

29  Yellow  Transparent 41 

Total.  .  320 


7 

4 

2 

4 

6 

11 

19 

6 

15 

20 

2 

22 

5 

1 

1 

29 

10 

4 

3 

3 

5 

2 

17 

1 

2 

3 

5 

9 

27 


82 
519 
214 
592 

1  279 
187 

1  742 
234 
364 

1  585 
347 

2  281 

85 
533 

14 

4  000 

219 

1  226 

44 

75 
446 
316 
346 

34 

74 
104 

69 
771 
894 


21 

8 

10 

132 

542 

111 

355 

25 

30 

304 

99 

443 

42 

31 

•4 

794 

.72 

256 

6 

53 

120 

44 

63 

16 

23 

22 

41 

264 

294 


245 


18  676 


4  225 


Malus  forms  on  which  used  is  also  given  together  with  the  flowers 
pollinated  and  the  fruits  matured. 

Considering  the  320  matings  from  the  side  of  the  male  parents, 
202  were  made  in  the  greenhouse  and  118  in  orchard.  Dividing  the  101 
failures  as  to  location,  72  of  them  occurred  in  the  greenhouse  and  29  in 
the  orchard;  together  these  failures  include  3,283  pollinations,  about 
17.5  percent,  which  can  not  be  considered  an  excessive  or  unexpected 
proportion  of  the  whole  number  of  pollinations.  Most  failures,  partic- 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  425 

ularly  those  in  the  greenhouse,  involved  small  numbers  of  flowers.  The 
larger  proportion  of  flowers  to  matings  in  the  orchard  was  due  to  a  few 
matings  in  which  the  numbers  of  flowers  were  unusually  large  and 
which  failed  entirely  from  some  undetermined  cause,  as  for  example 
the  pollination  of  369  flowers  of  M.  arnoldiana  (802)  by  Jonathan, 
201  flowers  of  M.  niedwietzkyana  (834)  by  Jonathan,  286  flowers  of 
M.  baccata  (806)  by  Grimes,  and  202  flowers  of  M.  floribunda  (821) 
by  Arkansas.  These  swell  the  number  of  pollinations  that  failed,  and 
with  at  least  three  of  the  mother  plants  given  it  is  probable  that 
repetition  of  the  combinations  would  give  entirely  different  results. 
Failures  are  shared  by  twenty  of  these  pollen  plants;  there  are  nine 
varieties  used  in  twenty- four  matings  for  which  no  complete  failures 
are  recorded. 

Performance  of  Some  of  the  Pollen  Varieties 

Oldenburg  was  more  frequently  used  for  supplying  pollen  than 
any  other  variety.  Pollen  of  this  variety  was  used  in  52  matings  on 
29  of  the  44  forms  of  Malus  and  pollinated  4,000  flowers  which 
developed  794  fruits.  The  greenhouse  matings  number  37,  12  of  which, 
with  162  flowers,  failed  in  fruit  production,  and  of  15  matings  on 
orchard  trees,  3,  with  195  flowers,  failed.  The  greenhouse  matings 
that  failed  covered  a  relatively  small  number  of  flowers,  an  average  of 
only  13.5  to  each  mating.  The  three  failures  in  orchard  were  on  two 
of  the  Malus  forms;  one  on  M.  halliana  (823),  with  106  flowers,  in 
1916,  and  two  on  Yellow  Siberian  Crab,  one  with  48  flowers  in  1909, 
and  one  with  41  flowers  in  1913.  Success  with  Oldenburg  pollen  has 
been  so  general  that  it  is  believed  the  causes  of  recorded  failures  may 
rightly  be  ascribed  to  defects  in  the  pistillate  plants,  to  inability  to 
function  in  the  case  of  first  flowers  borne  by  small  trees  in  greenhouse, 
to  the  same  cause  in  the  case  of  M.  halliana  in  orchard,  and  to  general 
infertility  on  the  part  of  Yellow  Siberian  Crab,  which  has  already  been 
referred  to  as  infertile  with  7  different  varieties. 

Oldenburg  has  large  anthers,  produces  viable  pollen  in  abundance, 
and  is  regarded  as  one  of  the  best  pollenizers  available.  Because  of 
the  estimation  in  which  this  pollen  is  held  it  has  been  more  frequently 
used  than  any  other,  has  been  chosen  for  extreme  and  doubtful  matings, 
and  hence  has  a  success  percentage,  as  computed  from  the  aggregates 
of  flowers  and  fruits,  slightly  lower  than  the  general  average  for  all 
pollinations. 

Yellow  Transparent  is  next  to  Oldenburg  in  the  number  of 
matings  in  which  used;  the  record  covers  41  matings  with  27  forms  of 
Malus;  38  of  these  were  in  the  greenhouse  and  only  3  in  orchard. 
Preponderance  of  inside  matings  is  due  to  the  possession  of  two  potted 
trees  which  supplied  pollen  in  the  first  years  of  work  under  glass  when 
other  varieties  were  not  available.  Of  the  38  greenhouse  matings,  12 


426  BULLETIN  No.  275  [June, 

failed  to  develop  fruits  as  did  also  one  of  the  3  matings  in  orchard. 
This  failure  in  orchard  was  the  pollination  of  43  flowers  of  Yellow 
Siberian  Crab,  which  was  equally  sterile  with  pollen  of  6  other  var- 
ieties. The  greenhouse  failures  involved  101  flowers,  approximately 
one-ninth  of  all  flowers  pollinated  by  this  variety.  The  aggregate  of 
flowers  pollinated  was  894,  from  which  294  fruits  developed,  giving 
32.88  as  the  percentage  of  success.  This  is  considerably  higher  than 
the  percentage  for  all  varieties,  which  is  22.62.  Some  of  the  higher 
degrees  of  success  attained  by  pollen  of  Yellow  Transparent  were  on 
M.  baccata  oblonga  (811),  where  49  flowers  gave  48  fruits,  or  were 
97.96  percent  successful,  on  M.  ringo  (840) ,  where  27  flowers  gave  25 
fruits,  or  were  92.57  percent  successful,  on  M.  sargenti  (843)  where  11 
flowers  gave  10  fruits,  or  were  90.91  percent  successful,  on  M.  mains 
var.  (19667)  where  2  matings,  one  of  9,  the  other  of  7  flowers,  were  100 
percent  successful.  Yellow  Transparent  is  rated  equal  to  Oldenburg  in 
abundance  and  vitality  of  its  pollen. 

Domine  was  used  as  a  pollenizer  in  29  matings  with  19  different 
forms  of  Malus.  The  total  of  flowers  pollinated  was  1,742,  and  of  the 
fruits  matured,  355;  this  gave  a  success  percentage  of  20.37.  The 
division  of  matings  between  greenhouse  and  orchard  was  13  for  the 
greenhouse  and  16  for  the  orchard.  All  matings  in  the  orchard  were  in 
some  degree  successful,  percentages  ranging  from  2.08  percent  for  one 
fruit  from  48  pollinations  of  Yellow  Siberian  Crab  flowers  to  82.35 
percent  for  28  fruits  from  34  flowers  of  M .  prunijolia  (838) .  The  suc- 
cess percentage  from  the  aggregates  of  pollinations  in  orchard  was 
21.50.  Four  of  the  13  greenhouse  matings  with  81  flowers  failed;  the 
9  matings  producing  fruit  had  a  range  of  success  percentages  from  6.82 
for  3  fruits  from  44  pollinations  of  flowers  of  M.  floribunda  (821)  to 
69.23  percent  for  9  fruits  from  13  pollinations  of  flowers  of  M.  ringo 
(840) ;  because  of  the  four  failures  the  success  percentage  of  green- 
house pollinations  fell  to  13.78.  Domine  pollen  may  be  said  to  have 
been  highly  acceptable  to  stigmas  of  flowers  of  M.  prunijolia  var. 
(838),  to  M.  ringo  (840),  and  to  M.  toringo,  dwarf  form  (19664); 
reasonably  acceptable  to  M.  sylvestris  jastigiata  bifera  (820),  to  M. 
baccata  maxima  (810),  to  M.  atrosanguinea  (804),  and  to  M.  dioica 
(819) ;  much  less  acceptable  to  M.  jloribunda  (821),  and  to  M.  pruni- 
jolia xanthocarpa  (839) ;  and  to  have  been  refused  by  M.  malus  var. 
(830),  by  M.  microcarpa  (19644),  by  one  of  2  matings  with  M.  pruni- 
jolia xanthocarpa  (839),  and  by  one  of  2  matings  with  M.  prunijolia 
var.  (19651). 

However,  it  must  be  remembered  that  in  all  cases  of  refusal  of 
pollen  and  of-  low  percentages  of  success  the  condition  of  the  pistillate 
parent  or  of  the  pistils  themselves  constitutes  an  important  factor  and 
may  have  been  such  as  to  absolve  the  pollen  parent  from  any  suspicion 
of  deficiency.  There  is  abundant  evidence  that  the  relation  of  any 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  427 

particular  pollen  plant  to  any  particular  pistillate  plant  is  inconstant, 
varying  greatly  with  seasonal  and  physiological  factors,  and  any  defi- 
nite conclusion  as  to  the  desirability  of  a  plant  or  variety  as  a  pollen- 
izer  for  another  must  rest  upon  a  much  greater  number  of  matings 
than  are  here  under  consideration.  Domine  pollen  falls  readily  from 
the  anthers,  is  powdery,  of  high  vitality,  and  the  variety  is  given  place 
as  a  desirable  pollenizer,  but  statement  of  its  virtue  for  use  on  a  par- 
ticular variety  or  form  of  Malus  must  be  held  in  abeyance  pending 
more  extended  trials. 

Grimes  was  used  in  32  matings  on  20  different  forms  of  Malus; 
there  were  1,585  pollinations,  which  matured  304  fruits.  Greenhouse 
matings  numbered  21  with  219  flowers  and  61  fruits,  those  in  orchard 
numbered  11  with  1,366  flowers  and  243  fruits.  Failures  recorded 
include  seven  with  57  flowers  for  greenhouse  and  three  with  464  flowers 
for  orchard.  The  ratios  of  fruits  to  flowers  pollinated  were,  for  green- 
house pollinations  1  to  3.59,  for  pollinations  in  orchard  1  to  5.62,  or  for 
the  aggregate  of  all,  1  fruit  for  each  5.21  flowers  pollinated.  As  with 
other  varieties  the  greenhouse  pollinations  involved  small  numbers  of 
flowers,  an  average  of  about  10.5  to  each  mating,  while  the  average  for 
trees  in  orchard  was  a  fraction  over  124  flowers  to  each  mating.  Suc- 
cess percentages  for  the  different  matings  had  a  rather  wide  range  from 
a  fraction  of  1  percent  for  257  pollinations  on  M.  ringo,  in  the 
orchard,  which  yielded  1  fruit,  to  100  percent  for  2  matings  under 
glass,  one  of  10  flowers  on  M.  toringo  (19664),  and  the  other  of  7 
flowers  on  M.  mains  var.  (19667).  Grouping  all  matings  in  the  green- 
house, the  success  percentage  was  27.85,  for  those  in  orchard,  17.78, 
and  for  the  aggregate  without  reference  to  location,  19.18  percent. 

Grimes  is  regarded  as  a  good  pollenizer  and  for  most  cases  of 
failure  and  low  percentages  of  success  appearing  in  this  record  the 
cause  is  believed  to  rest  with  the  pistillate  parent. 

Jonathan  is  very  similar  to  Grimes,  as  may  be  seen  by  its  record, 
and  the  two  are  held  in  equal  estimation  as  pollen  parents.  Jonathan 
was  mated  twenty-six  times  with  22  different  forms  of  Malus.  The 
number  of  flowers  pollinated  was  2,281,  and  443  fruits  were  matured. 
The  percentage  of  success  was  19.42,  which  differs  but  little  from  that 
attained  by  Grimes. 

Seed  Production  and  Distribution  in  Group  3 

Fruits  matured  from  the  crosses  of  Group  3  total  4,225  and  the 
aggregate  of  seeds  saved  was  20,179,  or  an  average  of  4.77  seeds  to 
each  fruit.  In  assembling  the  records  for  examination  of  seed  produc- 
tion it  was  found  that  for  three  of  the  Malus  forms  the  totals  included 
some  fruits  that  did  not  have  complete  seed  records;  they  were  fruits 
that  had  been  invaded  by  codling  moth  larvae  and  the  cores  eaten  to 
such  extent  that  no  accurate  record  of  seeds  was  possible,  or  that  thru 


428  BULLETIN  No.  275  [June, 

some  other  cause  had  incomplete  seed  records.  Such  apparently  good 
seeds  as  were  found  in  these  fruits  were  saved,  but  there  was  no  way 
of  determining  either  distribution  or  full  number  produced.  Because 
of  the  incomplete  record,  these  fruits  and  the  seeds  they  produced  are 
not  included  in  the  tabulated  seed-production  records.  The  forms 
affected  and  the  number  of  fruits  and  seeds  eliminated  were  as  follows: 

M.  baccata  oblonga  (811) — 17  fruits  with  lt)7  seeds 
M.  prunijolia  var.  (838)— 73  fruits  with  310  seeds 
M.  toringo  (19664)— 18  fruits  with  26  seeds 

Adding  these  various  numbers  and  deducting  from  the  total  leaves 
4,117  fruits  and  19,736  seeds  to  be  included  in  the  distribution  tabula- 
tion, giving  an  average  of  4.79  seeds  to  each  fruit.  Recalling  the 
average,  7.05  seeds  to  each  fruit,  as  determined  for  Group  1,  and  that 
of  7.14  seeds  to  each  fruit  as  found  for  Group  2,  it  appears  that  Group 
3,  in  which  the  pistillate  parents  were  all  crab-like  forms  of  Malus, 
had  a  very  much  lower  average  seed  production  than  had  either  of  the 
groups  in  which  the  pistillate  parents  were  orchard  varieties.  The 
average  of  4.79  seeds  to  each  fruit  is,  however,  distinctly  higher  than 
the  average  3.78  seeds  to  each  fruit  as  found  for  5,007  naturally  fertil- 
ized fruits  of  22  crab-like  forms  of  Malus  as  reported  in  Bulletin  203. 

The  range  in  seed  production,  as  appears  in  Table  16,  is  0  to  16, 
with  only  1  fruit  of  one  of  the  forms  of  M.  spectabilis  reaching  the 
maximum;  the  number  next  below  the  maximum,  12  seeds  to  the  fruit, 
is  reached  in  1  fruit  of  the  same  form  that  contains  the  maximum  and 
also  in  4  fruits  of  M.  baccata  maxima  (810) ;  the  next  number  lower, 
11  seeds  to  each  fruit,  is  represented  by  1  fruit  each  of  4  different 
forms  of  Mains,  and  in  the  column  for  10  seeds  to  each  fruit,  which  is 
taken  as  the  normal  content  for  apples,  there  appear  107  fruits  distrib- 
uted among  15  of  the  Malus  forms  in  numbers  from  1  to  30.  There 
were  thus  117  fruits,  or  2.84  percent  of  the  total,  that  reached  normal 
or  above  in  seed  production.  The  highest  frequency  falls  at  4  seeds  to 
each  fruit,  with  a  representation  in  this  column  of  538  fruits,  or  13.06 
percent  of  the  total,  distributed  among  33  of  the  45  Malus  forms. 
Numbers  in  the  four  columns  representing  2,  3,  4,  and  5  seeds  to  each 
fruit  are  very  nearly  equal  and  aggregate  2,110  fruits,  or  51.25  percent 
of  all  fruits.  Parthenocarpic  fruits  number  46  and  represent  14  forms 
in  numbers  from  1  to  22 ;  5  forms  each  have  1  such  fruit,  6  forms  have 
2  each,  1  has  3,  1  has  4,  and  M.  ringo  sublobata  (854)  has  22,  which 
is  2.73  percent  of  the  803  fruits  of  this  form.  Fruits  producing  1  seed 
each  number  353  and  are  distributed  among  27  forms  of  Malus  in 
numbers  from  1  to  70.  Four  of  the  44  forms  of  Malus  are  not  repre- 
sented by  fruits,  and  of  the  40  fruiting  kinds  8  are  represented  by  less 
than  10  fruits  each,  and  25  have  less  than  100  fruits  each,  so  that  for 
a  large  proportion  of  the  fruiting  forms  there  is  insufficient  basis  from 
which  to  judge  their  possibilities  in  seed-production  accurately. 


1926] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


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430  BULLETIN  No.  275  [June. 

Period  of  Fruit  Maturity 

The  period  of  fruit  harvest  for  hybrids  of  Group  3  extended  from 
June  2  to  October  31.  Pollinations  in  the  greenhouse  were  begun  Feb- 
ruary 26  and  continued  until  March  21 ;  descriptions  of  resulting  fruits 
were  begun  June  2  and  ended  September  28.  The  first  fruits  maturing 
were  those  of  M.  dioica,  from  pollinations  of  February  26  and  28, 
which  were  described  June  2  and  7;  next  following  were  fruits  of  M. 
spectabilis  (849) ,  described  June  22,  and  then  M.  sylvestris  fastigiata 
bifera  (820) ,  July  10.  Others  matured  at  intervals  until  the  last  fruits 
of  M.  soulardi  and  M.  ioensis  were  described  September  28.  From 
orchard  pollinations  early  in  May  the  first  fruits  maturing  were  those 
of  M.  baccata  sieboldi  (814) ,  M.  baccata  maxima  (810) ,  M.  prunifolia 
macrocarpa  (837),  and  Florence  Crab,  all  of  which  were  described 
August  17-19;  then  follow  M.  sylvestris  fastigiata  bifera  (820),  on 
September  1;  M.  siberica  frutico  coccinea  (19643),  M.  mains  var. 
(830),  Hyslop  Crab,  and  General  Grant  Crab,  September  11  to  15;  M. 
microcarpa,  September  25,  and  finally  others  of  the  baccata  group,  the 
forms  of  M.  prunifolia,  M.  floribunda,  and  its  allies  M.  atrosanguinea 
and  M.  arnoldiana,  and  the  forms  of  M.  toringo  with  which  may  be 
classed  M.  sargenti,  and  last  of  all  M.  ioensis;  these  extended  the 
season  of  fruit  description  to  the  last  of  October.  With  the  forms  last 
mentioned  there  is  much  latitude  in  regard  to  time  for  harvesting. 
Usually  the  fruits  are  fully  colored  by  October  1  and  are  ready  to  pick 
at  any  time  between  that  date  and  the  first  killing  frost. 

Loss  of  Seeds  Between  Extraction  and  Planting 

The  seeds  saved  from  the  4,225  fruits  number  20,179;  there  were 
planted  19,743,  showing  a  loss  of  436  seeds  in  the  period  between 
extraction  and  planting,  or  2.15  percent  of  the  number  saved.  This  is 
a  much  smaller  percentage  of  loss  than  is  recorded  for  either  of  the 
other  groups  considered ;  for  Group  2  the  loss  percentage  is  more  than 
twice  as  large  as  for  Group  1  and  more  than  three  and  one-half  times 
as  large  as  for  Group  3.  Storage  periods  were  not  materially  different 
for  seeds  of  the  different  groups;  for  Group  3  the  periods  were,  for 
seeds  from  fruits  from  greenhouse  pollinations  69  to  187  days,  and  for 
seeds  from  fruits  from  orchard  pollinations  36  to  117  days. 

The  seeds  of  Group  3  were  produced  by  214  matings,  and  of  these 
136  showed  no  loss,  the  number  saved  and  the  number  planted  being  in 
each  case  the  same;  the  losses  were  then  distributed  among  78 
matings,  in  24  of  which  the  loss  was  but  one  seed  each.  The  largest 
loss  occurred  in  a  mating  of  M.  prunifolia  var.  (838)  with  Rome,  in 
which  31  fruits  contained  246  seeds,  only  207  of  which  were  planted,  a 
loss  of  39  seeds;  next  to  this  was  a  loss  of  30  seeds  in  the  mating 
General  Grant  Crab  with  Domine.  One  mating  lost  28  seeds,  one,  24, 
another,  22;  beyond  this  the  losses  were  less  than  20  and  mostly  very 


1926] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


431 


small.    The  seed  losses  in  this  group  were  small,  no  larger  than  was  to 
be  expected,  and  need  no  further  comment. 

Percentage  of  Germination  Lower  in  Group  3 
Than  in  Other  Groups 

Seeds  planted  from  the  hybrid  fruits  of  Group  3  numbered  19,743 ; 
of  these  10,857,  or  54.99  percent,  are  recorded  as  having  germinated 
(Table  17).  This  percentage  is  decidedly  lower  than  for  the  other 
groups;  for  Group  1,  62.22  percent  germinated  and  for  Group  2,  71.99 
percent.  Examination  of  percentages  of  germination  for  individual 

TABLE  17. — NUMERICAL  RELATION  OF  LIVING  SEEDLINGS  TO  SEEDS  GERMINATED  INT 
GROUP  3,  CRAB-LIKE  FORMS  OF  MALUS  X  ORCHARD  VARIETIES,  WITH 
PERCENTAGES  AND  AGES  OF  TREES 


Year 

Number 
of 
raatings 

Seeds 
germi- 
nated 

Seedlings  living 

Age  of 
trees, 
yrs. 

Number 

Percentage 

1909  

1 
4 
23 
11 
46 
26 
66 

7 
35 
1  151 
576 
1  982 
2  132 
4  974 

6 
13 
731 
329 
1  068 
1  780 
4  298 

85.71 
37.14 
63.51 
57.11 
53.88 
83.48 
86.40 

7 
5 
4 
3 
2 
1 
X 

1911  

1912  

1913  

1914  

1915  

1916  

Total  

177 

10  857 

8  225 

75.77 

matings  does  not  disclose  any  definite  reason  why  the  general  average 
of  the  group  was  below  that  of  other  groups.  For  a  large  proportion 
of  the  matings  the  germination  was  fairly  good,  and  in  some  it  was 
high.  In  four  matings  all  seeds  germinated,  but  the  numbers  of  seeds 
were  small;  in  three,  the  percentage  is  above  90,  and  twelve  other 
matings  have  percentages  ranging  between  80  and  90.  The  group  giv- 
ing least  satisfactory  results  is  that  of  M.  sargenti;  this  species 
was  the  pistillate  parent  in  eleven  matings  with  eight  different  pollen 
plants;  two  produced  no  fruits;  seven  of  the  nine  yielding  fruits  had 
a  total  of  182  seeds,  all  of  which  failed  to  germinate.  M.  sargenti  X 
Grimes  produced  21  seeds,  12  of  which,  or  57.14  percent,  germinated, 
and  M.  sargenti  X  Yellow  Transparent  produced  18  seeds,  only  1  of 
which  germinated.  Brief  mention  may  be  made  here  of  the  perform- 
ance of  some  of  the  groups  of  crosses  having  the  largest  numbers  of 
seeds.  M.  prunifolia  var.  (838)  from  fifteen  matings  with  13 
orchard  varieties  produced  1,611  seeds  that  were  planted,  of  which 
1,295,  or  80.38  percent,  germinated;  M.  ringo  from  twenty-seven 
matings  with  11  orchard  varieties  had  1,075  seeds  planted,  656  of 
which,  or  61.02  percent,  germinated;  M.  baccata  maxima  (810) 
from  eight  matings  with  5  varieties  produced  2,152  seeds  that  were 
planted,  1,548,  or  71.93  percent,  of  which  germinated.  M.  flori- 


432  BULLETIN  No.  275  [June, 

bunda  (821)  from  fourteen  matings  with  11  varieties  gave  368  seeds 
and  germinated  197,  or  53.53  percent,  and  M.  arnoldiana  (802)  from 
seven  matings  with  5  varieties  produced  420  seeds,  289,  or  68.81 
percent,  of  which  germinated.  Aside  from  the  matings  of  M.  sar- 
genti,  already  referred  to,  in  which  only  13  of  221  seeds,  or  5.88 
percent,  germinated,  there  are  no  groups  with  such  low  percentages  as 
to  attract  attention  or  need  special  comment. 

Hybrid  Seedlings  Now  Living 

Hybrid  seedlings  resulting  from  pollination  of  flowers  of  the  vari- 
ous crab-like  forms  of  Mains  by  pollen  of  orchard  varieties  in  the 
years  1909  and  1911-1915  numbered,  late  in  the  fall  of  1916,  3,927,  and 
to  these  may  now  be  added  the  seedlings  grown  from  seeds  of  fruits 
developed  from  the  pollinations  of  1916.  These  seedlings  were  planted 
in  nursery  about  three  months  ago  and  have  been  recently  enumerated 
in  order  to  eliminate  any  that  died  in  the  interval  since  planting. 
Growing  conditions  have  been  unusually  favorable,  losses  have  been 
very  small,  and  the  living  seedlings  are  exhibiting  a  degree  of  vigor 
above  the  experience  of  most  seasons.  These  young  seedlings  number 
4,298,  and  represent  86.4  percent  of  the  number  recorded  in  the  record 
of  germination ;  adding  these  to  the  seedlings  of  preceding  years  gives 
8,225  as  the  total  of  living  seedlings  in  Group  3;  they  represent  177 
distinct  matings  and  142  different  combinations  of  parent  plants. 

The  numbers  of  seedlings  under  the  different  combinations  of 
parents  varies  between  1  and  990;  there  are  18  combinations  each 
represented  by  one  seedling,  20  that  have  two  seedlings  each,  41  that 
have  each  about  50,  and  of  these  20  have  above  100  seedlings  each. 
Naturally  the  larger  groups  are  among  those  that  have  been  exposed, 
for  the  shortest  periods  of  time,  to  accidents  and  to  the  influences  that 
combine  to  eliminate  weak  individuals,  but  among  the  seedlings  of 
1912  are  six  groups  with  more  than  50  each,  and  two  have  above  100. 
All  seedlings  to  and  including  those  of  1914  have  been  planted  in 
orchard,  while  the  others  are  in  nursery.  Distribution  of  the  seedlings 
by  years,  with  percentages  and  age,  are  given  in  Table  17. 

Detailed  Performance  of  Some  Crab-like  Forms  on 
Which  Pollen  of  Orchard  Varieties  Was  Used 

Behavior  of  a  few  of  the  Malus  forms  that  have  been  most  freely 
used  may  here  be  given  in  detail  to  show  their  reaction  to  pollen  of 
orchard  varieties. 

M.  prunifolia  var.  (838). — Because  of  its  prolificacy,  this  vari- 
ety has  been  somewhat  of  a  favorite;  it  flowers  and  fruits  regularly 
and  abundantly,  and  has  served  as  the  pistillate  parent  in  fifteen 
matings;  four  in  orchard  in  1911,  seven  in  orchard  in  1912,  two  in 
greenhouse  and  one  in  orchard  in  1914.  and  one  in  orchard  in  1915. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  433 

One  of  the  matings  of  1912  repeated  one  of  1911,  and  the  one  in 
orchard  in  1914  repeated  a  mating  of  1912,  so  that  the  fifteen  matings 
represent  13  distinct  combinations  of  parents.  With  the  one  exception 
of  the  pollination  of  nine  flowers  with  pollen  of  Stayman  Winesap,  in 
the  greenhouse  in  1914,  all  matings  produced  fruits  ranging  in  numbers 
from  3  for  the  cross  with  Arkansas  to  142  for  the  cross  with  Collins. 

The  aggregate  of  flowers  pollinated  was  770  and  of  fruits  matured 
421,  a  success  percentage  of  54.67,  and  a  ratio  of  one  fruit  for  each  1.82 
flowers  pollinated.  There  were  2,236  seeds  saved  from  the  421  fruits, 
an  average  of  5.31  from  each  fruit;  the  number  of  seeds  planted  was 
2,111,  showing  a  loss  of  125  seeds,  or  5.59  percent,  in  the  interval  of 
dry  storage  between  extraction  and  planting.  Of  the  2,111  seeds 
planted  1,295,  or  61.34  percent,  are  recorded  as  having  germinated. 
Seedlings  living  at  ages  from  one  to  five  years  number  899  and  repre- 
sent 69.42  percent  of  those  appearing  in  the  germination  record.  An 
apparent  discrepancy  in  numbers  of  fruits  and  seeds  may  be  referred 
to  and  explained  here.  In  the  tabulation  of  seed  distribution  for  the 
forms  of  Malus,  this  variety  appears  as  having  but  348  fruits  and  1,926 
seeds,  while  in  this  detailed  account  of  the  variety  the  number  of  fruits 
is  given  as  421  and  the  number  of  seeds  as  2,236.  This  difference  arises 
from  the  fact  that  73  fruits  had  no  record  of  seed  distribution  and 
hence  they  and  the  310  seeds  they  produced  were  omitted  from  the 
tabulation.  The  actual  production  for  the  variety  was  421  fruits  and 
2,236  seeds  (Table  18) . 

M.  ringo  sublobata  (854  and  19689). — This  variety  was  used 
as  the  pistillate  parent  in  nineteen  matings  with  14  different  orchard 
varieties  (Table  19).  Five  matings  are  duplicated,  four  in  different 
years;  one  pollen  variety,  Collins,  was  used  twice  in  one  year,  but  the 
matings  were  on  different  trees  and  so  are  listed  separately.  Nine  of 
the  matings  were  on  trees  in  orchard  and  ten  were  made  in  the  green- 
house; those  made  under  cover  were  limited  in  numbers  of  flowrers  by 
the  youth  and  size  of  available  trees,  and  the  same  is  true  of  the  1912 
matings  in  orchard.  For  orchard  matings  in  later  years  bloom  was 
abundant  and  the  numbers  of  flowers  utilized  were  easily  increased. 
Six  matings  which  together  represented  70  pollinations  failed  entirely; 
two  of  these  were  in  1912  on  an  orchard  tree  flowering  for  the  first 
time  and  failure  was  ascribed  to  imperfections  in  the  flowers;  the 
other  four  were  greenhouse  matings,  two  with  Yellow  Transparent,  one 
with  Grimes  and  one  with  Fanny,  and  nothing  is  known  of  the  cause 
of  failure.  Considering  all  matings,  including  those  that  failed 
entirely,  it  appears  that  44  percent  of  the  pollinations  were  successful ; 
this  is  nearly  double  the  percentage  for  the  group  and  compared  with 
the  percentage  for  the  aggregate  of  apple  pollinations  may  be  regarded 
as  high.  Seed  production  for  this  variety  is  low;  the  average  number 
of  seeds  for  each  fruit  is  3.61  as  compared  with  an  average  of  4.79  for 


434 


BULLETIN  No.  275 


[June, 


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1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  437 

the  group  to  which  the  variety  belongs,  or  with  the  average  of  5.31 
seeds  for  the  variety  of  M.  prunifolia  previously  considered. 

M.  floribunda  (821). — As  an  illustration  of  the  performance, 
when  pollinated  by  orchard  varieties,  of  one  of  the  species  producing 
very  small  fruits,  the  record  of  M.  floribunda  may  be  given. 

Flowers  of  this  species  were  pollinated  by  11  orchard  varieties  in 
fourteen  matings  distributed  over  five  years.  One  mating  in  each  of 
the  years  1914,  1915,  and  1916  was  made  in  the  greenhouse,  all  others 
were  on  trees  in  orchard.  Two  of  the  inside  matings,  those  with 
Yellow  Transparent  and  Oldenburg,  failed  as  did  also  the  orchard 
matings  with  Jonathan,  Fanny,  and  Arkansas.  Such  fruits  as  were 
borne  were  the  product  of  nine  matings  with  six  varieties.  Percentages 
of  success  were  low  for  all  matings;  the  highest  was  for  the  mating 
with  Fameuse  in  1912,  which  was  28.57  percent,  and  the  lowest  for  a 
fruit-producing  mating  was  the  1916  mating  with  Osimoe,  in  which  331 
flowers  pollinated  yielded  six  fruits,  or  1.81  percent  (Table  20).  For 
all  pollinations  the  success  percentage  was  6.21 ;  in  other  words  it  re- 
quired the  pollination  of  approximately  16  flowers  to  produce  one 
fruit.  M.  floribunda  is,  perhaps,  the  most  difficult  to  pollinate  success- 
fully of  any  form  of  Malus  in  the  collection.  Buds  are  so  small  and  the 
stamens  so  closely  associated  with  the  pistil  that  extreme  care  in 
emasculating  is  necessary  to  avoid  injury  to  styles  or  ovary.  It  is 
probable  that  failures  and  low  percentages  of  success  were,  in  no  small 
part,  due  to  injuries  inflicted  at  time  of  emasculation. 

GROUP  4:     CRAB-LIKE  FORMS  OF  MALTJS  X 
CRAB-LIKE  FORMS  OF  MALUS 

This  group  of  hybrids  is  much  smaller  than  the  other  groups, 
chiefly  for  the  reason  that  attention  has  naturally  centered  upon  those 
groups  in  which  the  combinations  of  parents  included  established  and 
well-known  varieties.  Where  one  or  both  of  the  plants  combined 
already  possess  qualities  giving  them  economic  standing,  the  possibili- 
ties seem  greater  that  the  progeny  may,  thru  some  readjustment  of 
the  aggregate  of  good  qualities,  exhibit  improvement  over  either 
parent,  than  in  combinations  between  plants  having  little  or  no  eco- 
nomic value.  Plant  improvement  is  a  principal  aim  in  breeding,  and  it 
is  logical  to  follow  that  procedure  which  in  the  judgment  of  the  breeder 
offers  the  best  opportunities  for  successful  accomplishment  of  the  end 
in  view.  But  from  the  standpoint  of  a  study  of  character  transmission 
hybrids  of  Group  4  are  no  less  interesting,  no  less  important  than 
hybrids  of  the  preceding  groups;  there  is  even  the  possibility  that 
combinations  of  these  very  diverse  forms  may  prove  to  be  of  more 
value  than  any  of  the  combinations  involving  what  are  conventionally 
referred  to  as  highly  developed  varieties  —  varieties  that,  in  some 
unexplained  manner,  have  become  possessed  of  qualities  that  make 


438 


BULLETIN  No.  275 


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440  BULLETIN  No.  275  Uunc, 

them  economically  valuable  and  worthy  of  being  perpetuated.     The 
crab-like  forms  of  Malus  have  been  under  the  disturbing  influences  ofl 
cultivation  for  a  much  shorter  period  than  have  the  orchard  varieties 
developed  from  M.  mains;  they  are  not  remotely  removed  from  wild! 
types,  their  characters  have  not  been  greatly  modified  from  those 
of  the  primitive  forms,  they  reproduce  thru  seeds  with  great  con- 
stancy. Orchard  varieties,  on  the  contrary,  can  be  maintained  only  by 
vegetative  propagation ;   multiplied  thru  seeds  they  do  not  come  true ; 
there  is  prompt  retrogression  to  forms  nearer  the  originals  in  charac- 
ters and  therefore  of  little  or  no  value.    Characters  of  the  crab-like 
forms  may  be  assumed  to  possess  greater  stability,  to  be  more  fixed, ; 
and  more  likely  to  be  transmitted  as  unmodified  units.     That  some] 
characters  are  more  potent  than  others  and  more  likely  to  dominate  in 
the  progeny  is  probably  true,  and  behavior  of  hybrids  between  plants 
that  are  believed  to  possess  such  characters  will  be  watched  with  in- 
terest. 

Thus  far  56  combinations  of  parents  have  been  attempted  in  this 
group;  the  flowers  pollinated  numbered  1,068  and  the  fruits  matured 
305,  a  ratio  of  1  fruit  for  each  3.56  pollinations  (Table  21).  Seven  of; 
the  combinations — including  302,  or  27.6  percent — of  all  flowers  pollin- 
ated, and  yielding  124,  or  40.65  percent  of  the  fruits,  were  on  trees  inj 
orchard.  Forty-nine  of  the  combinations — with  766,  or  71.72  percent, 
of  all  flowers  pollinated,  and  176,  or  58.66  percent,  of  fruits  matured — 
were  on  potted  trees  in  the  greenhouse.  The  numbers  of  flowers  pollin- 
ated in  the  different  combinations  are,  in  general,  small;  the  largest 
number  was  93  flowers  of  Whitney  pollinated  in  1911  by  Yellow 
Siberian  Crab  and  producing  28  fruits;  the  smallest  number  was  four] 
on  M.  ringo  sublobata  pollinated  by  Whitney  in  the  greenhouse  in 'I 
1915  and  failing  in  fruit  production;  the  average  for  all  combinations 
is  about  18.5  flowers.  Of  the  56  combinations  19  failed  to  develop 
fruits;  these  were  all  in  the  greenhouse  and  included  229  pollinations, 
or  21.44  percent  of  the  total.  Five  of  the  Malus  forms  used  as  pistil- 
late parents  failed  entirely  in  fruit  production;  these  were  M.  baccata 
maxima  (810)  with  5  flowers  pollinated  by  M.  baccata  (806) ;  the 
Fluke  Apple  (822)  with  11  flowers  pollinated  by  M.  niedivietzkyana 
(834) ;  M.  mains  pendula  (19688)  with  18  flowers  pollinated  by  M. 
ringo  (19662);  M.  soulardi  with  15  flowers  pollinated  by  M.  nied- 
luietzkyana,  and  5  flowers  pollinated  by  M.  mains  var.  (19667),  and 
three  combinations  with  M.  ringo  sublobata  as  follows:  26  flowers 
pollinated  by  M.  microcarpa  (19644),  4  by  Whitney,  and  17  by  M. 
prunifolia  xanthocarpa.  This  leaves  the  37  fruit-producing  combina- 
tions distributed  among  20  of  the  forms  of  Malus  used  as  mother 
plants.  The  success  percentage  for  the  group  as  a  whole  was  28.09; 
this  was  somewhat  higher  than  for  the  other  groups,  in  which  the  per- 
centages of  success  are  recorded  as  follows:  Group  1,  12.90;  Group  2, 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  441 

15.83;  and  Group  3,  22.63.  For  individual  combinations  the  range 
for  the  37  that  produced  fruits  was  from  3.22  percent  for  a  greenhouse 
combination,  in  which  50  flowers  of  M.  toringo  pollinated  by  M.  nied- 
wietzkyana  yielded  two  fruits,  to  75  percent  for  a  combination  in 
which  8  flowers  of  M.  ringo  pollinated  by  M.  niedwietzkyana  pro- 
duced six  fruits.  In  four  combinations  less  than  10  percent  of  the  flow- 
ers pollinated  developed  fruits,  and  13  combinations  in  each  of  which 
more  than  50  percent  of  the  flowers  pollinated  developed  fruits. 

Because  of  the  small  number  of  matings  in  this  group  the  tabula- 
tion of  parental  combinations  may  take  a  different  form  from  that 
adopted  in  presenting  the  larger  groups,  and  instead  of  combining  all 
matings  for  each  pistillate  parent  they  may  be  individually  entered, 
thus  giving  in  detail  the  behavior  of  each  pair  with  results  brought 
down  to  the  last  enumeration  of  seedlings. 

The  number  of  Malus  forms  appearing  in  the  56  matings  tabu- 
lated is  29,  and  of  this  number  17  appear  as  both  pistillate  and  pollen 
parents,  8  appear  only  as  pistillate  parents,  and  4  only  as  pollen 
parents.  This  list  of  matings  is  not,  as  a  whole,  what  would  be  chosen 
if  it  were  possible  to  arrange  in  advance  a  schedule  of  desired  pollina- 
tions. Most  of  the  pollinations  were  made  in  the  greenhouse  on  small 
trees  bearing  few  flowers;  these  trees  did  not  all  bring  flowers  to 
receptive  condition  at  the  same  time,  but  spread  the  flowering  period 
over  several  weeks.  For  this  reason  many  of  the  combinations 
attempted  were  those  of  convenience  rather  than  choice.  Effort  was 
made  to  utilize  receptive  flowers  at  the  proper  time  and  it  was  neces- 
sary to  use  such  pollen  as  was  available  at  the  time.  There  was 
no  inclination  to  deprecate  this  procedure,  because  no  other  course 
seemed  possible,  and  when  it  is  considered  that  nothing  definite  is 
known  regarding  the  heritable  qualities  of  the  tangible  characters  of 
these  plants,  it  is  evident  that  the  basis  on  which  selection  of  parents 
may  rest  is  insecure  and  not  dependable.  When  progeny  of  these 
matings  are  grown  to  flowering  age  and  pollinations  are  to  be  made 
as  an  initial  step  toward  a  second  generation,  the  case  will  be  quite 
different.  Immediate  parents  of  the  plants  will  be  known,  charac- 
ters will  have  been  studied,  compared  with  those  of  the  parents,  and 
definite  impressions  formed  as  to  what  matings  would  be  desirable. 
When  that  time  comes  plants  that  are  to  be  mated  must  be  brought 
to  flower  simultaneously;  this  can  be  accomplished  thru  the  study  of 
vegetative  and  flowering  records,  which  will  enable  right  decision 
regarding  time  of  starting  growth  and  temperatures  necessary  for 
the  proper  rate  of  development. 

Seed  Production  and  Distribution  in  Group  4 

The  number  of  seeds  saved  from  the  300  fruits  was  1,600,  an 
average  of  5.33  to  each  fruit.  This  average  is  higher  than  for  hybrid 


442  BULLETIN  No.  275  [June, 

fruits  of  Group  3,  in  which  the  average  was  4.77  seeds  to  each  fruit, 
but  considerably  lower  than  the  average  of  7.14  seeds  to  -each  fruit  in 
Group  2,  or  the  average  of  7.06  seeds  for  each  fruit  in  Group  1. 
Individual  varieties  or  species  have  averages  ranging  from  1.5  seeds 
to  each  fruit  for  4  fruits  of  M.  prunifolia  xanthocarpa  and  4  fruits 
of  the  dwarf  form  of  M.  toringo,  to  8  seeds  to  each  fruit  for  14 
fruits  of  M.  mains  var.  (830).  The  maximum  was  12  seeds  for 
one  fruit  of  M.  spectabilis  var.  (849).  Four  parthenocarpic  fruits 
are  recorded,  three  for  M.  dioica  and  one  for  M.  mains  var.  (19667). 
The  range  of  seeds  for  all  fruits  was  thus  0  to  12.  There  were  30 
fruits  with  7  seeds  each.  This  was  the  highest  frequency.  The  normal 
of  10  seeds  to  each  apple  was  reached  by  12  fruits  and  but  3  fruits  had 
seeds  above  this  number,  2  fruits  with  11  seeds  each  and  the  one 
already  mentioned  having  the  maximum  of  12. 

The  purpose  of  Table  22  is  to  show  seed  distribution  in  the  fruits 
produced  from  the  matings  within  the  group;  therefore,  only  those 
combinations  producing  fruits  are  included.  The  19  crab-like  forms 
of  Malus  listed  in  the  table  have  representation  in  48  combinations, 
but  11  of  these  combinations,  distributed  among  nine  of  the  mother 
plants  included  in  the  list,  failed  in  fruit  production  and,  therefore, 
are  excluded,  leaving  a  total  of  37  fruit-producing  combinations  dis- 
tributed among  the  19  different  forms  of  Malus.  In  this  tabulation  the 
totals  of  fruits  and  seeds  are  less  than  those  given  in  the  preceding 
table;  this  is  because  37  of  the  fruits  produced  by  M.  prunijolia  (838) 
had  no  record  of  seed  distribution  and  hence,  having  no  proper  place  in 
this  table,  are  omitted;  these  37  fruits  produced  160  seeds,  150  of  which 
were  planted,  but  only  9  germinated. 

Losses  of  Seeds  Between  Extraction  and  Planting 

The  seeds  planted  were  less  by  51  than  the  number  saved;  a  loss 
of  3.13  percent,  a  percentage  somewhat  higher  than  that  for  Group  3, 
but  lower  than  for  Group  2,  and  less  than  half  the  loss  in  Group  1. 

Percentages  of  Germination  Vary  Widely 

Of  the  37  combinations  producing  seeds,  six  with  an  aggregate  of 
63  seeds  failed  entirely  in  germination;  six  other  combinations  with 
an  aggregate  of  44  seeds  record  only  one  germination  each ;  one  other 
combination  germinated  two  seeds  and  one  three  seeds;  above  these 
the  numbers  for  different  combinations  ranged  from  5  to  101.  Per- 
centages ranged  from  2.75  for  3  seeds  germinated  out  of  109  planted 
from  the  23  fruits  of  M.  prunifolia  var.  (838)  X  Yellow  Siberian 
Crab,  to  93.33  percent  for  14  germinated  out  of  15  seeds  planted  from 
the  2  fruits  of  M.  mains  var.  (830)  X  M.  prunifolia  var.  (19651). 
For  all  combinations  the  seeds  germinated  numbered  753,  or  48.61 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


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444  BULLETIN  No.  275  [June, 

percent  of  those  planted;  30.02  percent  germinated  in  Group  3,  71.99 
percent  in  Group  2,  and  62.22  percent  in  Group  1. 

Hybrid  Seedlings  Now  Living 

From  the  753  seeds  germinated  within  the  group  there  are  now 
living  439  seedlings,  distributed  according  to  age  as  follows: 

From  pollinations  of  1911  and  now  in  the  6th  year—  152 
From  pollinations  of  1912  and  now  in  the  5th  year  =  27 
From  pollinations  of  1913  and  now  in  the  4th  year  =  33 
From  pollinations  of  1914  and  now  in  the  3d  year  =  137 
From  pollinations  of  1915  and  now  in  the  2d  year  =  2 
From  pollinations  of  1916  and  now  in  the  1st  year  =  88 

Those  seedlings  from  pollinations  of  the  four  earlier  years  are 
planted  in  orchard.  They  number  349,  or  79.49  percent  of  the  group 
total.  The  others  are  in  nursery  and,  like  the  earlier  ones,  will  be 
given  permanent  positions  when  two  years  old.  The  living  seedlings 
represent  58.30  percent  of  the  seeds  germinated,  a  percentage  less 
than  for  any  of  the  other  groups;  the  record  for  Group  1  is  73.67  per- 
cent; for  Group  2,  73.98  percent;  and  for  Group  3,  66.21  percent. 

For  the  lots  of  different  ages  the  percentages  of  germinations  per- 
sisting as  seedlings  range  from  37.5  percent  for  the  lot  of  33  trees  now 
in  their  fourth  year,  to  87.12  percent  for  the  88  seedlings  from  ger- 
minations of  last  spring.  The  seedlings  now  in  their  sixth  year  repre- 
sent 64.40  percent  of  the  germination  in  1911  and  unless  attacked  by 
disease  or  killed  thru  accident  they  should  all  reach  fruiting  age. 
Younger  lots  are  more  likely  to  meet  with  losses,  but  examination  of 
the  seedlings  indicates  that  for  all  lots  the  elimination  of  constitu- 
tionally weak  individuals  has  been  already  accomplished,  so  that 
except  for  some  unusual  catastrophe,  such  as  might  occur  from  winter 
cold  or  summer  storm,  it  is  expected  that  further  losses  will  be  small. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  445 

THE  GENUS  MALUS 

The  genus  Malus  instituted  by  Tournefort1  in  1700  included  five 
species;  one  of  these,  sylvestris,  has  two  varieties;  under  another, 
saliva,  the  cultivated  apple,  are  recorded  twenty-nine  varieties.  The 
names  and  descriptive  phrases  used  are  credited  to  earlier  writers, 
among  whom  are  Ruellio,  1536,  and  C.  Bauhin,  1623  and  1671.  Sev- 
eral are  credited  to  the  "Hortus  Regius  Parisiensis,"  a  work  published 
in  1665.  Malus,  the  apple  genus,  was  separated  from  Pirus,  the  pear 
genus,  on  form  characters.  Linnaeus  in  1735  used  the  Latin  term  Pirus 
generically  to  designate  the  apple  family,  including  all  pomaceous 
fruits,  and  Malus  became  the  specific  name  of  cultivated  apples  and 
their  supposed  originals. 

Notwithstanding  various  efforts  to  separate  them,  apples  and 
pears  remained  in  the  genus  Pyrus  until  1897,  when  Britton  and 
Brown2  reestablished  the  genus  Malus,  basing  the  separation  upon  the 
single  character,  the  presence  in  pears  and  the  absence  in  apples  of 
grit-cells  in  the  flesh.  Earlier  attempts  to  segregate,  based  upon  dis- 
tinct styles  in  pears  and  more  or  less  connate  styles  in  apples,  failed 
because  of  the  inconstancy  of  the  character;  in  like  manner  red  anthers 
are  not  characteristic  of  all  pears  any  more  than  yellow  anthers  are 
characteristic  of  all  apples;  so  too,  all  apples  are  not  umbilicate  at 
both  base  and  apex,  nor  are  all  pears  umbilicate  at  apex  only.  For 
the  great  majority  of  both  pears  and  apples  there  are  characters  which 
readily  distinguish  the  one  from  the  other,  but  these  characters  are 
not  universal  thruout  the  respective  genera.  The  separation  of  apples 
and  pears  by  Britton  and  Brown,  on  the  presence  or  absence  of  grit- 
cells  is  generally  accepted,  but  Carriere3  has  pointed  out  that  this 
character,  like  others  that  have  been  referred  to,  is  not  perfectly  con- 
stant; he  cites  Malus  sempervirens  (synonym  of  Pyrus  [Malus] 
angustifolia,  according  to  "Index  Kewensis")  as  an  example  of  an 
apple  whose  fruits  very  often  contain  these  grit-cells.  Carriere  adds 
that  there  is  scarcely  an  organic  character  that  is  truly  differential 
between  apples  and  pears  unless  it  be  the  presence  in  apples  of  an  acid 
which  is  said  not  to  exist  in  pears,  but  the  constancy  of  this  character 
this  writer  does  not  care  to  affirm. 

The  apples  constitute  a  natural  group  as  worthy  of  distinction  as 
are  many  other  botanical  groups  which  in  rare  instances  fail  in  those 
characters  which  separate  them  from  closely  allied  groups.  The  apple 
genus  contains  very  diverse  forms;  there  are  low  straggling  shrubs  and 
tall  fastigiate  trees,  flowers  that  range  in  spread  from  10  mm.  to  60 
mm.,  and  fruits  from  the  size  of  small  peas  to  those  above  4  inches  in 


'Tournefort,  J.  P.    Inst.  Rei  Herb.    1700. 
'Britton  and  Brown.    Illus.  Fl.    1897. 
'Carriere,  E.  A.    Rev.  Hort.,  295.    1881. 


446  BULLETIN  No.  275  [June, 

diameter,  but  they  are  all  apples  and,  with  few  exceptions,  are  readily 
recognized  as  such.  That  there  is  great  confusion  in  the  nomenclature 
of  the  species  of  the  genus  is  a  fact  of  which  any  one  who  undertakes 
classification  of  the  forms  will  soon  become  convinced.  Britton  and 
Brown  accord  fifteen  species  to  the  genus,  but  the  names  that  have 
been  used  to  designate  apple  forms,  regarded  as  good  species  by  the 
authors,  reach  a  number  far  in  excess  of  this. 

The  "Index  Kewensis,"  issued  in  1895  and  supposed  to  contain  all 
plant  names  used  up  to  1885,  lists  318  specific  names  under  the  genus 
Pyrus.  The  authors  recognize  95  of  these  names  as  valid  and  223  are 
considered  as  synonyms.  About  70  of  the  specific  names  belong  to  the 
Malus  section  of  the  genus,  possibly  a  little  in  excess  of  this  number, 
for  there  are  a  few  names  that  cannot  be  located,  even  in  section, 
without  consulting  original  sources  that  are  not  available. 

Sections  of  the  genus  other  than  Malus,  as  Pyrus,  Sorbus,  Mes- 
pilus,  Aria,  and  Crataegus,  are  represented  by  210  names.  Of  the 
names  known  to  belong  to  Malus,  18  are  retained  as  valid  while  the 
rest  are  listed  as  synonyms.  Twenty-five  of  the  names  applied  to 
forms  of  Malus  are  recorded  as  synonyms  of  the  one  species  Pyrus 
mains,  the  common  apple.  J.  C.  Loudon1  under  the  genus  Pyrus  lists 
20  species,  11  of  which  are  pears  and  9  apples.  Martyn's  Miller's  Dic- 
tionary of  1807  lists  13  species  of  Pyrus;  3  are  pears,  8  are  apples,  and 
2  are  quinces. 

The  number  of  names  used  as  specific  designations  of  forms  of 
apple  is  sufficient  to  show  wide  variations,  and  the  large  proportion  of 
names  that  have  been  relegated  to  lists  of  synonyms  indicates  differ- 
ences in  judgment  on  the  part  of  those  botanists  who  have  worked 
with  the  group.  Doubtless  a  considerable  number  of  the  specific  desig- 
nations were  based  upon  differences  too  slight  or  too  ephemeral  to 
stand  the  test  of  time  and  examination  of  more  abundant  material; 
others  that  are  still  recognized  as  species  may  and  very  likely  will  be 
discarded  by  the  monographer  who  attempts  a  complete  revision  of  the 
genus.  The  51  forms  received  for  breeding  purposes  include  31  with 
specific  names:  3,  namely,  Hyslop  Crab,  Yellow  Siberian  Crab,  and 
Fluke  Apple,  that  appear  under  their  common  names  only;  2  are  un- 
named forms;  while  the  remaining  15  are  varieties  of  M.  baccata,  M. 
prunifolia,  M.  toringo,  and  M.  mains.  Included  among  the  varieties 
are  7  hybrids  as  follows:  M.  baccata  X  M.  prunifolia,  M.  baccata  X 
M.  toringo,  M.  mains  X  M.  baccata,  all  of  the  800  series,  and  M. 
baccata  X  M.  mains  (3549) ,  M.  baccata  X  M.  floribunda,  M.  mains  X 
M.  baccata,  and  M.  baccata  X  M.  toringo  of  the  19000  series.  These 
hybrids  all  proved  to  be  weak ;  while  some  of  the  scions  started  growth 
after  grafting,  all  finally  died  and  passed  out  of  the  collection. 


'Loudon,  J.  C.    Arboretum  et  Fruticetum  Britannicum  2.    1838. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  447 

All  of  the  species  and  varieties  included  in  the  Malus  collection 
have  produced  flowers  and  fruit,  and  a  large  proportion  of  them  have 
been  used  in  breeding.  To  record  as  accurately  as  possible  the  char- 
acters possessed  by  each  form  that  has  entered  into  any  of  the  par- 
ental combinations,  detailed  descriptions  are  necessary,  and  these  now 
follow  alphabetically  as  nearly  as  can  be  and  still  bring  together  those 
forms  appearing  under  the  same  specific  name. 

DESCRIPTION  OF  MALUS  FORMS  USED  IN  BREEDING 
1.  Malus  angustifolia  Michx.  (19676,801,1204) 

First  recorded  by  Aiton1  as  Pyrus  angustifolia.  Placed  in  the 
genus  Malus  by  Michaux  in  1803. 

Nuttall  (1818),  Torrey  (1826),  Eaton  (1833),  Gray  (1860),  Chap- 
man (1883),  and  other  botanists  retained  Alton's  position  for  the  plant 
under  Pyrus.  Britton  and  Brown  (1897)  restored  it  to  Malus.  This 
has  been  included  in  each  of  our  three  series.  As  19676,  one  root-graft 
was  made  March  23,  1907.  The  graft  grew,  but  is  described  as  very 
weak ;  it  was  alive  July  20,  1907,  but  died  in  the  early  fall. 

As  801,  ten  top-grafts  on  a  Sops  of  Wine  tree  were  made  April  4, 
1908.  Six  of  these  were  alive  in  the  fall  of  1908,  but  the  growth  was 
weak  and  the  various  grafts  died  during  the  summer  of  1909.  Ten 
root-grafts  were  made  January  17,  1908;  these  started  growth,  but 
only  two  were  living  in  the  fall ;  these  were  stored  for  the  winter  and 
replanted  in  the  spring  of  1909,  but  both  died  during  the  summer. 

As  1204  the  scions  were  root-grafted  on  apple  seedlings  January 
10,  1912.  On  October  23,  1912,  six  of  ten  made  were  living  and  the 
average  growth  for  the  season  was  3.29  inches.  Two  of  the  trees  lived 
to  be  planted  in  orchard  April  14,  1914;  one  of  these  died  the  following 
year  and  one  survived  until  sometime  during  the  summer  of  1918. 
Death  of  these  trees  was  anticipated  because  of  the  very  feeble  growth 
from  the  beginning.  When  scions  were  received  in  1912,  some  were 
worked  on  both  paradise  and  Doucin  stocks;-  these  grafts  started 
growth,  but  died  before  the  end  of  the  season.  On  April  6,  1914,  two 
scions  taken  from  one  of  the  trees  root-grafted  in  1912  were  grafted  on 
paradise  stocks  growing  in  8-inch  pots.  One  of  these  is  in  the  green- 
house for  the  1924  season.  It  is  very  small  and  of  straggling  growth. 
It  flowered  sparingly  in  1918  and  in  each  year  since.  In  1918,  25 
flowers  pollinated  by  Twenty  Ounce  yielded  2  fruits  containing  13 
seeds,  8  of  which  germinated;  3  seedlings  lived  to  be  planted  in 
nursery,  2  were  living  in  1919,  one  in  1920,  and  this  died  in  1921. 
Also  in  1918,  9  flowers  pollinated  by  Fameuse  yielded  1  fruit  which 
contained  6  seeds,  5  of  which  germinated  and  produced  5  seedlings 
which  were  planted  in  nursery ;  one  of  these  survives,  is  5  years  old,  36 
inches  high,  21  inches  in  spread,  and  0.6  inch  in  trunk  diameter.  The 


'Aiton,  William.    Hort.  Kew.  ed.  1,  2,  176.    1789. 


448  BULLETIN  No.  275  [June, 

size  of  the  tree  does  not  indicate  vigor,  but  it  may  live  to  fruiting. 

The  experience  with  M.  angustifolia  here  detailed  shows  that 
it  does  not  succeed  on  any  stocks  tried,  nor  does  it  do  well  when  top- 
grafted  on  apple  varieties.  The  species  is  now  represented  by  one 
small  tree  on  Doucin  stock  in  a  pot  in  the  greenhouse  and  as  the  female 
parent  of  one  seedling  from  the  cross  by  Fameuse. 

A  small  tree  with  open-spreading  crown  and  rigid,  thorny 
branches;  native  in  the  South  and  known  as  the  Southern  Crab  or 
Narrow-leaved  Crab.  Leaves  lanceolate  or  narrowly  elliptical,  50  to 
80  mm.  long,  20  to  35  mm.  broad,  cuneate  at  base,  serrate  or  crenate- 
dentate  or  sometimes  nearly  entire,  apex  obtuse,  light  green,  rather 
thin,  but  rigid  and  shining,  pubescent  when  young,  becoming  glabrous; 
stipules  small,  very  narrow. 

Flowers. — Those  for  description  were  from  a  cluster  of  6  from  a 
lateral  bud  on  a  terminal  twig;  buds  oblong,  rounded  at  apex,  quite 
variable  in  size,  deep  pink.  Pedicels  16  mm.  long,  slender,  glabrous; 
calyx  lobes  narrowly  triangular,  acuminate,  erect,  of  medium  size,  gla- 
brous outside,  pubescent  inside;  petals  5,  ovate  with  rounded  apex, 
claw  4  mm.  long,  slender,  separated,  deep  pink.  Stamens  20,  filaments 
slender,  10  to  13  mm.  long,  anthers  large,  plump,  orange,  tinged  red; 
styles  slender,  tinged  red,  connate  at  base,  hairy  up  to  the  point  of 
separations,  stigmas  small,  capitate. 

Fruit.- — Roundish-oblate,  rather  pale  yellowish-green,  with 
rounded  regular  base  and  an  irregular  ribbed  apex,  of  medium  size 
from  the  crab  standpoint.  A  single  fruit  weighs  14.2  grams,  has  a  verti- 
cal diameter  of  25  mm.  and  a  transverse  diameter  of  31  mm.,  not  um- 
bilicate  at  base,  basin  of  medium  depth,  narrow,  acuminate,  irregular, 
dots  are  few,  small,  round,  white,  mostly  about  the  apex,  inconspicuous. 
Calyx  tube  is  large,  cylindrical,  of  medium  length,  core  small,  round, 
median,  closed,  core  lines  clasping,  cells  axile,  uniform,  carpels  obo- 
vate,  entire,  tufted,  concave;  seeds  of  medium  size,  plump,  dark;  flesh 
greenish,  firm,  crisp,  juicy,  very  acid;  stem  slender,  37  mm.  long,  erect, 
green,  glabrous;  calyx  small,  glabrous,  closed;  appears  like  fruit  of 
M.  coronaria  and  M.  ioensis  and  has  the  same  fragrance. 

M.  angustifolia  is  closely  related  to  M.  coronaria  and  by  some 
has  been  thought  to  be  only  a  variety  of  that  species.  Thomas  Nuttall1 
says  of  this  variety: 

"...This  appears  to  be  scarcely  more  than  a  variety  of  thePyrus  coronaria; 
distinguishable  indeed,  by  its  narrower  leaves,  usually  entire,  which  are  often 
acute  below;  but  as  the  styles  are  neither  perfectly  distinct  nor  constantly  glab- 
rous, and  that  the  young  leaves  are  also  pubescent,  no  sufficient  distinction  re- 
mains. The  fruit  is  likewise  wholly  similar." 

The  species  is,  however,  generally  accepted  as  valid  and  as  having  a 
southern  range  from  Pennsylvania  to  Florida,  and  west  to  Kansas  and 


'Nuttall,  Thomas.    N.  Amer.  Silva  1,  174.    1857. 


1936] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


449 


Louisiana.  M.  coronaria  is  more  northern,  ranging  from  western  New 
York  to  Wisconsin,  and  south.  Doubtless  the  ranges  of  the  two  species 
overlap  in  many  places  and  it  requires  no  stretch  of  the  imagination  to 
assume  that  there  are  intermediate  forms  so  nearly  like  the  respective 
species  as  to  be  almost,  if  not  quite,  indistinguishable.  If  the  tree  now 
in  the  greenhouse  continues  to  live  other  crosses  will  be  attempted,  but 
from  the  experience  up  to  this  time,  the  species  will  probably  never  be 
regarded  as  valuable  as  a  parent  in  breeding  at  this  Station. 

2.  Mains  arnoldiana  (802) 

This  species  was  described  in  the  plant  list  received  from  the 
Arnold  Arboretum  as  "a  seedling  of  M.  floribunda  that  originated  in 
the  Arnold  Arboretum  and  shows  the  influence  of  the  blood  of  M.  pru- 
nifolia  by  its  larger  flowers." 


FIG.  7. — TREE  OF  M.  arnoldiana  ON  MAY  9 
Flowers  are  produced  in  great  profusion,  both  from 
terminal  buds  of  shoots  and  spurs  and  from  lateral  buds 
of  shoots  of  the  previous  year. 

Scions  received  in  January,  1908,  were  root-grafted  on  apple  seed- 
ling stocks  January  17,  grown  two  years  in  nursery,  and  on  April  30. 
1910,  were  planted  in  orchard.  In  following  years  scions  from  these 
first  trees  grafted  were  worked,  both  as  root-grafts  on  common  stocks 
and  as  top-grafts  'on  orchard  varieties  and  on  paradise  stocks.  Trees 
grew  vigorously  and  several  of  them  have  been  flowering  and  fruiting 


450 


BULLETIN  No.  275 


[June, 


each  year  since  1912.  One  of  the  trees  grafted  in  January,  1908,  and 
now  16  years  old,  is  14^2  feet  high,  has  a  spread  of  19  feet,  2  inches, 
and  a  trunk  diameter  of  6.1  inches. 

Until  trees  are  seven  or  eight  years  old  they  are  very  symmetrical, 
with  rounded  somewhat  spreading  crowns;  after  this  age  the  rounded 
outline  becomes  somewhat  broken  by  protrusion  of  long  willowy 
shoots,  a  characteristic  which  is  very  pronounced  in  M.  floribunda 
and  all  descendants  from  that  species.  The  general  direction  of  the 
numerous  branches  is  ascending  and  somewhat  straggling.  Internodes 
are,  in  general,  short  to  medium,  l/2  to  %  inch  long. 

Flowers  are  produced  in  great  profusion,  both  from  terminal  buds 
of  shoots  and  spurs  and  from  lateral  buds  of  shoots  of  the  preceding 
year.  At  flowering  time  each  tree  is  a  dense  mass  of  bloom  and  very 
ornamental  (Fig.  7) .  Bark  of  trunk  light  grayish-brown,  smooth,  len- 
ticels  few,  small,  round  or  oval;  twigs  reddish-brown,  the  younger  with 
yellowish-green  tinge,  glabrous.  Buds  rather  small,  short,  thick, 
pointed,  reddish-brown,  glabrous. 

Leaves. — When  trees  are  in  flower  the  young  leaves  are  ^  inch 
to  2  inches  long,  various  in  form,  mostly  elliptical,  oblong  or  oval,  ta- 
pering at  base,  acute  or  acuminate  or  some  of  the  smaller  obtusely 
rounded  at  apex;  most  young  leaves  have  margins  quite  regularly  ser- 
rate, but  some  are  crenate- serrate;  when  young,  leaves  are  scantily 
pubescent  both  above  and  below,  becoming  glabrous  above  and  retain- 
ing a  few  hairs  along  the  midrib  below;  dark  green  above,  lighter 
below,  petiole  pubescent,  channelled. 

For  an  accurate  determination  of  range  in  size  100  leaves,  half 
from  terminal  shoots  and  half  from  lower  branches,  were  taken  by 
random  selection  and  measured  on  June  26;  dimensions  were  as 

follows: 

Top  terminal  Lower 

shoots  branches 


Length .maximum . 

minimum . 

average . . . 
Width maximum . 

minimum . 

average . . . 
Petiole  length,  .maximum. 

minimum . 

average . . . 


119mm. 
74  mm. 
97  mm. 
46  mm. 
21  mm. 
34  mm. 
33mm. 
17mm. 
23  mm. 

Top  terminal 


Apex  

.  .  .  .  Acute  

shoots 
37 

acuminate  

2 

obtuse  

11 

Margin.  .  .  . 

....  serrate  

34 

crenate  

0 

crenate-serrate  .  . 

16 

125  mm. 
42  mm. 
86mm. 
34  mm. 
14  mm. 
25  mm. 
40  mm. 
13  mm. 
28mm. 

Lower 
branches 
47 

0 

3 
12 

4 
34 


1986] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


451 


Leaves  from  top  terminal  shoots  are  somewhat  longer  than  those 
below,  but  the  lower  leaves  average  a  little  wider  and  have  longer 
petioles.  Stipules  are  %  to  %  inch  long,  lanceolate,  petiolate,  often 
with  one  or  two  pairs  of  teeth  or  small  lobes  near  the  base,  inclined  to 
persist. 

Flowers. — Each  mixed  bud  produces  from  5  to  7  small  leaves  and 
from  4  to  8  flower  buds;  these  are  terminal  and  lateral  on  spurs  and 
on  shoots  that  are  from  6  to  24  inches  long;  internodes  on  flowering 
shoots  are  mostly  short,  bringing  the  flowers 
so  close  together  that  when  open  they  are  in 
contact,  completely  obscuring  twigs  and 
leaves;  this  is,  in  part,  due  to  elongation  of 
the  bud  axis  which  may  amount  to  as  much 
as  %  inch  with  perceptible  separation  of  the 
leaf  and  flower  bearing  nodes.  Buds  are,  at 
first,  small,  globular,  and  dark  pink  in  color; 
as  they  approach  anthesis  they  become 
larger,  pointed,  and  much  lighter  in  color. 
Flowers  expand  35  to  37  mm.  and  are  mostly 
pure  white ;  occasionally  a  faint  pink  tinge  is 
retained.  Pedicels  slender,  green,  glabrous, 
bracteate,  averaging  35  mm.  in  length.  Ovary 
glabrous,  dull  red.  Calyx  lobes  lanceolate 
acuminate,  dull  red,  glabrous  outside,  pubes- 
cent within,  deciduous,  falling  soon  after 
flowering.  Of  4,000  fruits  examined  not  one 
retained  the  calyx  lobes.  Petals  oblong- 
ovate,  rounded  at  apex,  abruptly  contracted 
at  base  to  the  very  short  claw.  17  to  20  mm. 
long  by  8  to  10  mm.  in  width;  anthers  plump, 
oblong,  light  yellow.  Pollen  usually  abun- 
dant and,  after  dehiscence  of  the  anthers, 
tending  to  become  powdery;  not  cohering  in 
masses;  styles  3  or  4,  slender  8  to  10  mm. 
long,  connate  one-third  the  length,  hairy  in 
a  narrow  belt  about  the  point  of  separation; 
stigmas  oval,  oblique. 

Fruit. — Small,   round,    slightly    conical, 
tapering  towards  the  truncate  apex  to  the 

margin  of  the  russet  scar  left  by  the  deciduous  calyx  lobes ;  the  aver- 
age of  100  fruits,  weight  1.54  grams,  is  12  mm.  in  vertical  diameter 
by  13  mm.  in  transverse  diameter;  yellowish-white,  often  with  a 
bronze  or  pinkish  blush  where  exposed  to  the  sun;  no  bloom;  skin 
thin,  tough,  polished,  dots  none;  cavity  shallow,  narrow,  acute,  reg- 


FIG.  8. — SHOOT  OF  M.  Ar- 

noldiana  IN  FULL  FLOWER, 

APRIL  29 


452  BULLETIN  No.  275  [June, 

ular;  basin  a  plane  or  sometimes  very  slightly  depressed  surface 
outlined  as  a  russet  scar  with  a  minute  central  depression  that  repre- 
sents all  there  is  of  a  calyx  tube.  Stem  slender,  varying  from  25  to  40 
mm.  in  length,  glabrous,  yellow  streaked  with  red.  Core  large  in  pro- 


FIG.  9. — FRUITING  BRANCH  OF  M.  arnoldiana,  SEPTEMBER  16 
The  mature  fruits  are  a  pale  yellow.   A  considerable  propor- 
tion of  the  fruit  hangs  on  the  trees  until  the  buds  push  it  off 
in  the  spring. 

portion  to  the  size  of  fruit,  round,  closed,  core  lines  terminating  within 
the  limits  of  the  circular  apical  scar;  cells  axile,  round,  uniform;  car- 
pels obovate,  glabrous,  deeply  concave.  Seeds  plump,  of  medium  size, 
light  brown;  flesh  yellowish,  firm,  juicy,  acid,  astringent,  inedible.  A 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  453 

considerable  portion  of  the  fruit  persists  thru  the  winter,  falling  as 
the  buds  push  in  spring;  these  hold-over  fruits  are  brown  and  shriv- 
elled and  do  not  enhance  the  winter  aspect  of  the  trees. 

This  form  has  value  as  an  ornamental  when  in  bud  and  especially 
when  in  full  flower;  the  bloom  is  so  massed  as  to  be  conspicuous  and 
very  handsome.  A  twig  in  full  flower  is  shown  in  Fig.  8.  Again  in 
autumn  when  the  pale  yellow  of  mature  fruits  is  attained,  the  tree  is 
attractive,  but  not  so  conspicuous  as  are  some  of  the  crimson- fruited 
forms.  The  fruiting  stage  is  illustrated  in  Fig.  9  and  a  single  fruit  is 
shown  at  the  extreme  left  in  Fig.  44,  page  498. 

M.  arnoldiana  closely  resembles  M.  floribunda,  but  the  tree  is 
more  symmetrical,  the  bark  much  lighter  in  color,  the  flowers  much 
larger,  and  the  fruit  slightly  larger.  Buds  of  M.  floribunda  are  more 
deeply  colored  and  the  open  flowers  retain  more  pink  than  do  the  flow- 
ers of  M.  arnoldiana.  Calyx  lobes  are  deciduous  in  both,  and  both 
retain  fruits  thru  the  winter. 

3.  Mains  astracanica  (19670,803) 

Mains  astracanica  Dum.  Cours.,  ed.  2,  5,  426.    1811. 
Pyrus  astracanica  De  Candolle  Prodr.  2,  635.    1825. 

Given  as  a  synonym  of  Pyrus  mains  in  "Index  Kewensis."  This 
form  of  Malus  is  represented  in  the  collection  in  both  the  19000  series 
and  in  the  800  series.  It  has  propagated  readily  both  as  root-grafts 
and  as  top-grafts.  Top-grafts  began  flowering  at  four  years  from  the 
graft,  but  first  flowers  from  root-grafted  trees  did  not  appear  until  the 
ninth  year.  Bloom  has  been  scanty  on  all  trees  in  all  years,  with  the 
one  exception  that  a  top-grafted  tree  at  ten  years  of  age  in  1922  is  re- 
corded as  having  full  bloom.  Trees  are  very  vigorous,  upright  in  habit, 
with  dense  foliage.  Bark  of  trunk  light  brown  with  a  greenish  tinge,  of 
two-year-old  wood,  greenish-brown,  and  of  twigs  reddish-brown;  new 
shoots  pubescent;  internodes  %  to  l1/^  inches  long;  lenticels  numerous, 
small,  round. 

Leaves. — Large,  broadly  ovate  or  oblong,  3  to  5  inches  long,  l1/^ 
to  3  inches  broad,  acute,  crenate-dentate,  white  tomentose  on  both 
sides  when  young,  becoming  glabrous  above;  petioles  1  to  l1/^  inches 
long,  stout,  pubescent,  channelled;  stipules  14  to  %  inch  long,  linear, 
soon  falling  from  most  leaves.  Leaves  from  mixed  buds  are  ovate,  1 
to  2  inches  long,  acute  or  obtuse,  covered  both  sides  with  soft  white 
tomentum. 

Flower  buds  globular,  dark  pink,  fading  as  they  approach  anthe- 
sis.  Pedicels  short,  13  to  14  mm.  long,  stout,  densely  white  tomentose, 
bracteate;  ovary  gray,  pubescent. 

Flowers. — Calyx  lobes  5,  triangular,  acuminate,  7  mm.  long,  21/4 
mm.  wide  at  base,  pubescent  both  sides,  becoming  reflexed  even  before 
flowers  are  fully  open.  Flowers  expand  32  mm.  Petals  oval,  16  mm. 


454 


BULLETIN  No.  275 


[June, 


long,  12  mm.  broad,  white  inside,  but  more  or  less  spotted  with  pink 
on  outer  surface,  claw  broad,  1  mm.  long;  stamens  20,  filaments  slen- 
der, 5  to  8  mm.  long;  anthers  plump;  light,  creamy  yellow;  styles  short, 
8  mm.  long,  stout,  connate  for  5  mm.  from  base,  hairy  from  base  to 
point  above  separation,  tips  flattened,  irregularly  oval. 

Fruit. — The  fruit  described  was  the  first  fruit  matured  by  a  root- 
grafted  tree  in  its  ninth  year  and  was  picked  July  28,  1916;  it  weighed 
112.2  grams,  measured  54  mm.  in  vertical  and  70  mm.  in  transverse 
diameter;  oblate  in  form,  base  regular,  rounded,  apex  regular,  trans- 
verse section  obscurely  ribbed,  sides  equal;  ground  color  yellow, 
blushed  with  light  red  and  streaked  with  a  darker  red,  bloom  scanty, 


FIG.  10. — FRUIT  OF  M.  astracanica,  JULY  28,  NATURAL  SIZE 

waxy  white,  skin  smooth,  thin,  tough;  dots  many,  small,  round,  russet, 
most  numerous  about  apex,  inconspicuous;  cavity  shallow,  medium  in 
width,  obtuse,  regular;  basin  shallow,  medium  in  width,  obtuse, 
slightly  wrinkled;  stem  14  mm.  long,  slender,  clavate,  erect,  russet, 
pubescent;  calyx  rather  small,  pubescent,  closed.  Core  of  medium  size, 
cordate,  median,  half-open;  stamens  marginal,  core  lines  clasping; 
cells  axile,  uniform;  carpels  roundish,  entire,  glabrous,  concave;  seeds 
plump,  of  medium  size,  dark  brown.  The  5  cells  contained  9  plump 
seeds  and  1  undeveloped  ovule.  Flesh  yellowish,  tender,  juicy,  arom- 
atic, flavor  subacid,  good. 

From  observation  of  M.  astracanica  as  grown  here,  it  does  not 
appear  to  be  specifically  distinct,  but  should  have  place  as  a  variety  of 
M.  mains  in  the  Red  Astrachan  group. 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  455 

4.  Mains  atrosanguinea  (804) 

This  species  was  also  received  as  No.  19636  from  the  U.  S.  De- 
partment of  Agriculture.  The  list  accompanying  the  scions  carried  the 
following  note:  "Mains  atrosanguinea  is  probably  a  hybrid  between 
Mains  toringo  and  Mains  floribunda."  No  authority  for  the  species 
is  given  and  in  available  publications  the  name  is  not  to  be  found  ex- 
cept that  a  writer  in  "The  Garden"  does  use  atrosanguinea,  in  a  brief 
note,  as  a  varietal  name.  The  note  in  Vol.  27  (1885)  p.  247,  is  as  fol- 
lows: 

"Pyrus  floribunda  atrosanguinea,  this  is  a  hybrid  between  the  Japanese  Pyrus 
floribunda  and  the  Chinese  Pyrus  spectabilis,  both  very  free-flowering  and  very 
handsome  Crabs.  It  has  the  habit,  the  floriferousness  and  the  deep  color  of  the 
former  plant  and  the  large  flowers  of  the  latter.  It  is  said  to  be  an  excellent 
subject  for  forcing;  in  any  case  it  is  a  very  handsome,  hardy-flowering  shrub.  It 
originated  a  few  years  ago  in  one  of  the  Dutch  nurseries  and  no  doubt  ere  long 
when  better  known  will  be  widely  cultivated  in  this  country.  N." 

The  varietal  form  referred  to  here  may  be,  arid  probably  is,  dis- 
tinct from  the  form  received  here  as  a  species.  The  two  may  have 
come  from  entirely  different  sources  and  be  widely  different  in  their 
chief  characteristics,  but  in  the  absence  of  detailed  descriptions  upon 
which  the  form  names  were  founded  it  is  impossible  to  decide  upon 
the  validity  of  the  names  as  used. 

Propagation  of  the  scions  received  in  the  19000  series  was  suc- 
cessful, but  the  scions  had  been  so  reduced  in  vitality  by  drying  that 
growth  was  weak  and  the  plants  did  not  live  beyond  the  first  season. 

The  scions  received  in  1908  were  grafted  both  as  root-grafts  and 
as  top-grafts.  The  top-grafts  lived  and  made  a  feeble  growth  thru 
three  seasons  and  then  died.  Root-grafts  grew  vigorously  and  were 
planted  in  orchard  in  the  spring  of  1910.  One  of  these  trees  remains; 
the  others  were  removed  two  years  ago  in  thinning  the  plantation ;  this 
tree  as  measured  in  the  fall  of  1923  is  13  feet,  10  inches  high,  spreads 
21  feet,  9  inches,  and  has  a  trunk  diameter  of  7.6  inches.  It  is  now 
sixteen  years  from  graft  and  has  been  bearing  since  1912.  Other  trees 
were  propagated  in  1912  and  in  1914  and  the  form  is  well  represented 
in  the  collection. 

Tree. — Rather  low  and  very  wide  spreading,  producing  numerous 
rampant  shoots  which  give  a  straggling  appearance.  The  crown  is 
very  open;  shoots  are  mainly  ascending,  but  some  are  horizontal  and 
occasionally  drooping.  Internodes  are  of  medium  length,  %  to  1  inch 
long.  Bark  of  trunk  a  light  grayish-brown;  twigs  reddish-brown. 
Lenticels  numerous,  small,  oval,  conspicuous  on  young  wood.  Buds 
small,  broad,  obtuse. 

Leaves. — Very  variable  in  size,  1  to  4  inches  long,  the  smaller 
lanceolate  or  oblong,  or  very  small  ones  orbicular;  the  larger  ovate- 
lanceolate,  often  3-lobed;  mostly  crenate,  some  distinctly  serrate,  acu- 


456 


BULLETIN  No.  275 


[June, 


minate,  or  sometimes  acute;  glabrous  and  shining  above,  scantily 
pubescent  below,  very  dark  green  above,  light  green  below.  Petioles 
vary  from  stout  to  slender,  %  to  1  inch  long,  pubescent,  channelled; 
stipules  persistent,  lanceolate;  texture  leathery.  All  buds  on  wood  of 
the  preceding  year  do  not  start,  4  or  5  contiguous  buds  produce  leaves, 
while  the  adjoining  4  or  5  buds  remain  dormant.  This  gives  a  dis- 
continuous appearance  to  the  foliage. 

Flowers. — Flowers  are  borne  from  terminal  and  lateral  buds  of 
shoots  and  spurs,  the  great  majority  coming  from  lateral  buds  on  long 
shoots,  1  to  3  feet  long;  sometimes  the  flowering  is  continuous,  but  on 
many  shoots  there  are  groups  of  buds  that  produce  leaves  only,  and 

still  other  groups  that  remain 
dormant  so  that  the  flower 
masses  are  discontinuous;  this 
detracts  from  the  continuity 
of  color,  and  trees  in  full 
flower  are  not  so  attractive  as 
are  trees  of  M.  floribunda  and 
M.  arnoldiana.  A  branch  on 
which  flowering  is  nearly  con- 
tinuous is  shown  in  Fig.  11. 
Flower  buds  are,  at  first,  glob- 
ular, becoming  oval  just  be- 
fore opening  and  measuring  8 
mm.  in  length  by  5  mm.  in 
breadth,  very  deep  red.  A  twig 
of  this  species,  as  it  appeared 
in  bud,  April  21,  1915,  is 
shown  in  Fig.  12. 

The  individual  flower  ex- 
pands from  15  to  20  mm.; 
calyx  lobes  oblong,  acute,  dull 
purplish-red,  glabrous  outside, 
pubescent  within,  this  pubes- 
cence especially  dense  along 
the  margins.  Erect  in  bud, 
becoming  horizontal  in  open 
flowers.  Petals  oblong  or  el- 
liptical, 9  mm.  long  by  6  mm. 

broad,  rounded  at  base  to  the. very  short  claw;  in  bud  they  are  in- 
tensely dark  red,  but  fade  somewhat  when  expanded;  however,  in  no 
other  form  of  Malus  represented  in  the  collection  except  M.  niedwietz- 
kyana,  do  the  petals  retain  as  much  color  as  in  this — even  when  ready 
to  fall  they  are  of  a  distinct  reddish-pink  color.  Stamens  20,  fila- 
ments slender,  5  to  7  mm.  long,  anthers  light  yellow,  plump;  styles 


FIG.  11. — BRANCH  OF  M.  atrosanguinea  IN 

FLOWER,  APRIL  29.    FIG.  12.— TWIG 

IN  BUD,  APRIL  21 


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5,  slender,  8  mm.  long,  connate  one-third  the  length,  hairy  at  base, 
upper  half  tinged  red;  stigmas  oval.  Pedicels  22  mm.  long,  green,  more 
or  less  blotched  and  streaked  with  dull  red,  slender,  pubescent;  ovary 
pubescent,  dull  red. 

Fruit. — Small,  nearly  round,  the  longitudinal  diameter  usually 
slightly  longer  than  the  transverse  diameter.  The  average  of  100  fruits 
weighs  0.64  gram,  has  a  vertical  diameter  of  10  mm.,  and  a  transverse 
diameter  also  10  mm. ;  color  greenish-yel- 
low with  a  reddish-pink  blush  on  one  side; 
bloom  scant,  waxy  white;  skin  smooth, 
thin,  tough;  cavity  none;  basin  a  small 
russet  scar  scarcely  depressed;  no  calyx 
tube.  Calyx  lobes  deciduous,  but  not  so 
completely  as  in  either  M.  arnoldiana  or 
M.  floribunda;  of  2,037  fruits  examined, 
1,900  or  93.2  percent  had  lost  the  lobes, 
120  still  retained  the  lobes,  but  separation 
had  taken  place  and  they  were  apparently 
ready  to  fall;  in  16  fruits  the  lobes  were 
half  persistent,  that  is  to  say,  two  or  three 
of  the  lobes  had  become  separated,  had 
fallen,  or  were  ready  to  fall,  while  those 
remaining  were  still  fleshy  at  base  and 
plainly  persistent.  In  one  fruit  all  the 
lobes  had  fleshy  bases  and  were  truly  per- 
sistent. Core  large,  closed,  core  lines  not 
apparent;  cells  axile,  obovate;  carpels 
obovate,  entire,  glabrous,  deeply  concave; 
seeds  small,  light  brown;  flesh  yellowish, 

firm,  dry,  acid,  and  astringent.  Fruit  of  M.  atrosanguinea  is  illus- 
trated in  Fig.  13,  and  a  single  fruit  is  shown,  the  second  from  the  right 
in  Fig.  44,  page  498. 

M.  atrosanguinea  agrees  quite  closely,  in  its  characters,  with 
M.  floribunda;  but  not  so  closely  with  M.  taring o,  especially  as  re- 
gards habit  of  growth  and  foliage.  Still  there  appears  no  reason 
why  it  may  not  be  accepted  as  a  hybrid  between  these  two  species. 
M.  atrosanguinea  has  flowers  that  average  a  little  smaller  than  those 
of  M.  floribunda  or  M.  toringo;  its  fruits  average  a  little  larger  than 
those  of  either  of  the  assumed  parents.  Leaves  of  flowering  shoots  are 
quite  similar  in  the  three  forms,  but  on  non-flowering  shoots  they  are 
different ;  leaves  of  non-flowering  shoots  of  M.  floribunda  are  not  lobed 
and  are,  in  general,  shorter  and  broader  than  are  leaves  on  similar 
shoots  of  M.  atrosanguinea  and  M.  toringo. 


FIG.  13. — TWIG  OF  M.  atro- 
sanguinea  IN    FRUIT, 
SEPTEMBER  2 


458  BULLETIN  No.  275  [June, 

Mains  baccata  L.  Mant.  75  (1771) 

The  Siberian  Crab,  a  crab  with  berry-like  fruits,  is  represented  by 
numerous  forms,  many  of  which  have  been  given  varietal  names.  The 
forms  of  the  species  have  hybridized  freely  with  wild  forms  of  the 
common  apple  and  with  forms  of  other  species  until  it  is  doubtful  if 
the  original  form  can  ever  be  definitely  known.  The  species  as  at 
present  understood  ranges  over  Siberia,  Japan,  and  China,  and  in  those 
countries  has  been  cultivated  as  an  ornamental  for  a  long  period. 
Varieties  are  established  chiefly  upon  fruit  characters  and  they  exhibit 
wide  differences  in  form,  size,  and  color.  Dr.  Eduard  Regel,1  for  many 
years  Director  of  the  Imperial  Botanic  Garden  at  St.  Petersburg,  Rus- 
sia, in  "Gartenflora,"  a  journal  of  which  he  was  the  editor,  records 
seven  of  the  most  beautiful  varieties,  illustrating  the  fruits  by  a  hand- 
some colored  plate.  These  fruits  vary  in  transverse  diameter  from  10 
to  23  mm.,  in  color  from  yellow  to  bright  scarlet.  He  remarks  that 
there  are  many  other  forms  that  differ  widely  from  each  other. 

Scions  of  twelve  forms  of  M.  baccata  were  included  in  the  19000 
series  received  in  1907.  These  scions  were  root-grafted  and  most  of 
them  started  growth,  but  none  were  able  to  overcome  the  injury  from 
drying  in  transit  and  all  died  before  the  end  of  the  first  season.  Scions 
of  the  800  series  received  in  1908  included  eleven  forms  of  M.  baccata 
labelled  as  below: 

805  M.  baccata  aurantiaca  811  M .  baccata  oblonga 

806  M .  baccata  red  fruit  443-1  812  M.  baccata  X  prunifolia 

807  M.  baccata  bright  red  fruit,  late  813  M .  baccata  sanguinea 

808  M .  baccata  var.  814  M .  baccata  var.  sieboldi 

809  M .  baccata  var.  815  M .  baccata  X  toringo 

810  M.  baccata  maxima 

Scions  of  three  of  the  forms  did  not  grow  and  these  numbers  (805, 
812,  and  815,  the  two  latter  hybrids)  were  eliminated  the  first  season. 
The  scions  of  a  fourth  number  (809  M.  baccata  var.)  put  forth  shoots 
which  from  the  beginning  were  weak,  and  the  last  one  died  early  in  the 
fall  of  1910.  The  remaining  seven  forms  are  now  represented  by  trees 
and  six  of  them  have  been  used  in  breeding;  five  in  1913  and  the  three 
following  years,  and  one  in  1915  only.  The  seventh,  813  M.  baccata 
sanguinea,  is  later  than  the  others  in  flowering;  one  of  the  trees  pro- 
duced 2  flower  clusters  in  1915  when  seven  years  old,  and  again  in  its 
eighth  year  a  few  clusters  only.  Scions  from  one  of  the  trees  were 
grafted  on  dwarf  stocks  in  pots  in  February,  1911,  and  have  now  been 
in  the  greenhouse  for  twelve  winters;  these  trees  began  flowering  in 
1914,  the  fourth  year  from  graft,  and  have  fruited  each  year  since. 

These  forms  of  M.  baccata  may  be  described  in  the  order  of  the 
serial  numbers  beginning  with — 


'Regel,  Eduard.    Gartenflora  2,  201-203.    1853. 


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5.  Mains  baccata  (806) ,  red  fruit  443-1 

Five  trees  were  root-grafted  in  January,  1908;  all  grew  vigor- 
ously. Two  years  ago  four  were  taken  out. 

The  tree  remaining  is  now,  at  sixteen  years  from  graft,  19M>  feet 
high,  spread  17  feet,  and  is  6  inches  in  trunk  diameter.  The  habit  of 


FIG.  14.— TREE  OF  M.  baccata,  RED  FRUIT  (806) 

This  tree,  eight  years  from  graft,  shows  the 
erect  symmetrical  habit  of  growth  which  char- 
acterizes the  variety  (Cf.  807,  Fig.  15). 

growth  of  this  form  is  erect  and  symmetrical.  Bark  of  trunk  light 
greenish-brown,  of  two-year-old  twigs  gray-green,  of  new  shoots  green 
more  or  less  striped  with  dull  red.  Lenticels  numerous,  small,  round; 
young  shoots  pubescent,  soon  becoming  glabrous;  internodes  y*  to  iMj 


460 


BULLETIN  No.  275 


[June, 


inches  long.   This  variety  differs  from  the  next,  No.  807,  in  its  more 
strictly  erect  habit.    (Compare  Figs.  14  and  15.) 

Leaves. — Elliptical  to  broadly  ovate  or  some  of  the  smaller  oblong- 
ovate;  2^/2  to  4  inches  long,  acuminate,  serrate,  or  crenate-serrate  or 


FIG.   15. — TREE  OF   M.  baccata,   RED 

FRUIT,  LATE    (807) 

The  trees  of  this  variety  lack  the  symmetry 
of  variety  806.  They  have  widely  spreading 
branches  and  an  open  top.  This  tree  was  pho- 
tographed October  2,  eight  years  from  graft. 

sometimes,  in  part,  dentate.  Leaves  from  young  shoots  have  stout, 
pubescent  petioles  1  inch  long ;  from  buds  of  spurs  petioles  are  slender, 
1*4  to  2  inches  long,  nearly  glabrous.  Young  leaves  are  glabrous  above 
and  slightly  pubescent  along  the  ribs  below;  dark  green  and  shining 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


461 


above,  light  green  below.  Stipules  from  linear  to  lanceolate,   /4  to  % 
inch  long,  caducous;  texture  somewhat  leathery. 

Flowers. — Most  flowers  are  borne  from  terminal  and  lateral  buds 
on  terminal  shoots;  occasionally  from  terminal  buds  of  spurs  below, 
but  most  spurs  are  non-flowering.  On  some  shoots  every  node  has  its 


FIG.  16. — FRUITING  BRANCH  OF  M.  baccata,  RED  FRUIT 
(806-2),  SEPTEMBER  16 

flower  cluster  and  when  expanded  the  flowers  are  massed  together,  but 
on  other  shoots  only  a  portion  of  the  buds  bear  flowers  and  on  these 
leaves  are  more  conspicuous  and  the  color  less  massed.  Buds  5  or  6 
in  each  cluster,  pink,  but  fading  as  flowers  approach  anthesis;  pedicels 
slender,  40  mm.  long,  pubescent.  Calyx  lobes  5,  triangular  acuminate, 
pubescent  both  sides,  erect  in  bud,  becoming  reflexed  in  open  flowers, 
6  mm.  in  length.  Petals  5,  oval,  11  mm.  long  by  8  mm.  wide, 


462  BULLETIN  No.  275  [June, 

rounded  at  base  to  the  very  short  claw,  pure  white.  Flower  expands 
30  mm.  Stamens  range  in  number  from  11  to  20  with  an  average  for 
27  flowers  of  18;  filaments  slender,  5  to  8  mm.  long;  anthers  plump, 
light  yellow.  Styles  5,  slender,  12  mm.  long,  distinct  nearly  to  the  base, 
hairy  from  base  up  more  than  half  the  length;  stigmas  small,  round. 

Fruit. — The  ground  color  of  mature  fruits  is  a  clear  yellow,  the 
over-color  is  crimson  where  exposed  to  sun,  varying  to  lighter  red  tints 
in  shade.  The  coloring  is  handsome,  suggesting  certain  of  the  sweet 
cherries  in  the  shading  of  yellow  and  red.  The  form  is  oblate,  vertical 
diameter,  as  averaged  from  600  fruits,  20  mm.,  transverse  diameter 
25  mm.,  sides  equal,  bloom  scanty,  powdery;  skin  smooth,  thin,  tough; 
dots  few,  inconspicuous,  small  to  medium,  round,  white  or  sometimes 
russet;  cavity  shallow  to  medium  in  depth,  rather  narrow,  acute,  often 
somewhat  irregular;  stem  long,  26  to  36  mm.,  slender,  clavate,  green, 
often  streaked  with  red,  pubescent;  basin  shallow,  usually  rather 
broad,  obtuse,  generally  more  or  less  ribbed;  calyx  tube  small,  short, 
conical.  Calyx  lobes  not  so  completely  deciduous  as  are  those  of  M. 
arnoldiana  or  M.  floribunda.  Of  7,676  fruits  examined,  924,  or  12 
percent,  had  either  partially  or  wholly  persistent  lobes ;  88  percent  had 
deciduous  lobes,  but  the  deciduous  lobes  do  not  fall  so  early  as  in  some 
other  kinds;  some  altho  completely  separated  remain  until  maturity  of 
the  fruit.  Core  is  of  medium  size,  oblate,  median,  closed;  cells  axile, 
variable  in  size;  seeds  of  medium  size  and  of  a  medium  brown  color; 
flesh  yellowish,  firm,  juicy,  subacid,  astringent. 

A  fruiting  branch  as  it  appeared  September  16  is  shown  in  Fig.  16. 
This  variety  of  M.  baccata  is  attractive  when  in  flower  altho  the 
flowers  are  mostly  confined  to  the  extreme  top  of  the  tree  and  do  not 
present  such  masses  of  color  as  are  characteristic  of  M.  floribunda 
and  its  nearly  related  forms.  It  is  especially  attractive  in  autumn, 
because  of  the  brilliant  red  of  the  mature  fruit,  and  there  is  also 
something  pleasing  in  the  erectness  of  growth. 

6.  Mains  baccata  (807) ,  bright  red  fruit,  late 

As  with  the  preceding  variety  (806),  this  is  represented  in  the 
collection  only  in  the  800  series;  there  are  several  trees  from  grafts 
made  in  different  years.  The  oldest  from  grafts  made  in  January, 
1908,  is  sixteen  years  old  and  one  of  the  trees  measures  19  feet  2  inches 
high,  with  a  spread  of  17  feet,  and  trunk  diameter  of  7.6  inches. 

Tree. — Spreading  in  habit,  producing  long  slender  branches  which 
are  much  less  erect  than  are  similar  branches  of  806.  Altho  these  two 
varieties  of  M.  baccata  are  represented  by  trees  having  practically 
the  same  height  and  spread,  the  two  trees  are  very  different  in  appear- 
ance; the  first  (806)  is  quite  strictly  erect  with  thick  top;  the  second 
(807)  has  branches  widely  spreading,  open  top,  and  absence  of  that 


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symmetry  that  characterizes  806.  All  trees  grown  of  this  variety  are 
vigorous  and  healthy.  Internodes  short,  ^  to  %  inch  in  length,  buds 
small,  narrow,  acute;  bark  of  trunk  greenish-brown,  twigs  dark  brown; 
young  twigs  scantily  pubescent;  lenticels  irregular  in  distribution,  not 
numerous,  small,  in  part  round,  in  part  elongated.  A  tree  at  eight  years 
from  graft  is  shown  in  Fig.  15. 

Leaves. — Mostly  elliptical,  varying  to  ovate  or  obovate,  or  some 
of  the  smaller  orbicular,  1  inch  to  5l/2  inches  long  by  %  to  l1/^  inches 
wide;  acute  or  acuminate,  sharply  serrate,  glabrous  and  shining  dark 


FIG.  17. — TOP-WORKED  TREE  OF  M.  baccata  (807)  IN  FLOWER,  MAY  9 
FIG.  18. — FLOWERING  BRANCH  OF  SAME,  APRIL  29 


green  above,  scantily  pubescent  and  light  green  below;  petioles  slender, 
1 1/4  to  1  %  inches  long,  pubescent.  Laminae  taper  more  or  less  abruptly 
at  base;  texture  thin,  stipules  falling  early. 

Flowers. — Produced  from  terminal  and  lateral  buds  on  terminal 
shoots  as  well  as  from  terminal  buds  of  spurs  thruout  the  tree.  A  top- 
worked  tree,  four  years  from  graft,  in  flower  May  9,  1916,  is  shown  in 
Fig.  17.  Often  the  bud-axis  elongates  from  %  to  l/2  mcn  distinctly 
separating  the  leaves  and  in  some  cases  the  pedicels  as  well,  hence, 


464  BULLETIN  No.  275  [June, 

while  some  bud  clusters  appear  umbellate,  others  approach  the  raceme 
in  appearance;  buds  vary  from  4  to  8  in  each  cluster.  Flower  buds  glo- 
bular and  dark  cherry-red,  retaining  the  color  until  near  the  time  of 
opening;  they  become  oval  in  form  with  rounded  apex,  and  fade,  as 
they  open,  to  a  bright  pink  which  becomes  less  and  less  pronounced 
until  the  petals  are  nearly  white.  Flowers  do  not  become  pure  white 
as  in  806,  but  retain  a  more  or  less  pink  tinge  to  the  last.  Expanded 
flowers  measure  30  mm.  across.  Pedicels  long,  slender,  45' to  55  mm., 
pubescent,  green;  ovary  green,  densely  tomentose.  Calyx  lobes  5,  ob- 
long, acuminate,  pubescent  both  sides,  6  mm.  long,  erect  in  bud,  be- 
coming reflexed  in  open  flowers,  green  or  often  spotted,  or  streaked 
with  red  about  the  base.  Petals  5,  rounded  at  apex,  abruptly  rounded 
at  base  to  the  short,  but  distinct  claw;  15  mm.  long  by  9  mm.  broad, 
bright  pink  as  they  open,  but  soon  becoming  white  with  irregular  areas 
tinged  or  streaked  with  light  pink.  Stamens  18  to  20;  of  7  flowers 
from  1  cluster,  5  had  20  stamens  each  and  2  had  18  each;  filaments 
slender,  12  mm.  long,  connate  4  mm.  up  from  base;  densely  hairy  in  a 
band  about  the  point  of  separation ;  stigmas  oval.  A  flowering  branch 
photographed  April  29  appears  in  Fig.  18. 

Fruit. — This  variety  is  no  exception  to  the  rule  that  in  apples  var- 
iation in  size  of  fruit  is  extreme.  The  majority  of  fruits  on  a  given 
tree  may  present  a  uniform  appearance,  but  examination  brings  out 
that  the  extremes  are  widely  separated.  Data  on  weight  and  size  of 
115  fruits  of  this  variety  are  as  follows: 

Weight  Longitudinal  diameter             Transverse  diameter 

gms.  mm.                                          mm. 

Maximum 10.30      Maximum 25  Maximum 29 

Minimum 1.22       Minimum 13  Minimum 14 

Average 5.95      Average 20  Average 23 

The  form  is  roundish-oblate,  sides  usually  equal;  ground  color  of 
mature  fruits  is  yellow,  blushed  with  an  over-color  in  shades  of  red; 
the  more  exposed  fruits  become  bright  scarlet,  sometimes  over  nearly 
the  whole  surface,  those  less  exposed  are  less  covered  with  a  dull  brick- 
red.  The  variety  is  peculiar  in  that  the  colors  of  maturity  are  not 
assumed  until  very  late  in  the  fall ;  in  this  particular  it  is  quite  differ- 
ent from  806,  the  fruits  of  which  are  usually  highly  colored  before 
fruits  of  807  lose  the  green  of  immaturity.  This  variety  is  distinctly 
later  than  806.  It  is  from  three  to  five  days  later  in  flowering  in  spring 
and  the  fruit  is  not  mature  until  late  fall.  Even  during  the  last  days  of 
October,  after  hard  frosts,  the  fruits  are  much  less  highly  colored  than 
are  those  of  806. 

Bloom  is  scanty,  waxy,  gray;  skin  smooth,  polished,  of  medium 
thickness,  tough;  dots  few,  small,  regular,  round,  inconspicuous;  cavity 
shallow,  broad,  obtuse,  sometimes  ribbed;  stem  very  long,  40  to  55 
mm.,  slender,  more  or  less  clavate,  erect,  green,  slightly  pubescent; 


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465 


basin  shallow  or  none,  often  rounded  up  to  the  base  of  the  calyx  lobes, 
sometimes  ribbed;  calyx  lobes  of  medium  size,  about  5  mm.  long, 
obtuse,  erect,  connivent;  calyx  tube  small,  short,  urn-shaped.  This 
variety  affords  an  excellent  example  of  the  inconstancy  of  the  decidu- 
ous calyx  lobes  as  a  chief  character  distinguishing  the  forms  of  M. 
baccata  and  M.  toringo  from  those  of  M.  prunifolia  and  M.  mains. 
October  20,  1915,  the  fruit  of  5  trees  was  harvested,  counted,  each  in- 
dividual examined,  and  record  made  regarding  calyx  lobes  as  follows: 

Total  fruits 6,595 

Calyx  lobes  deciduous  and  fallen 2,164  or  32.8  percent 

Calyx  lobes  deciduous  but  still  adhering     356  or   5.4  percent 
Calyx  lobes  persistent 4,075  or  61.8  percent 

The  fruits  of  individual  trees  were  not  kept  separate,  but  it  was 
determined  before  harvesting  that  the  proportions  of  fruits  with  de- 
ciduous calyx  and  those  with 
persistent  calyx,  were  approx- 
imately the  same  for  the  differ- 
ent trees.  Those  fruits  in  which 
the  calyx  lobes  were  deciduous 
possessed  russet  scars  entirely 
similar  to  those  on  fruits  of  the 
variety  806.  In  those  fruits 
having  persistent  calyx  the 
lobes  were  in  all  cases  enlarged 
and  more  or  less  fleshy  at  the 
base,  appearing  much  as  in 
Figs.  7,  8,  and  11  of  Regel's 
colored  plate  No.  364  facing 
page  208  in  volume  2  of  "Gar- 
tenflora,"1  illustrating  varieties 
of  Pyrus  (Mains)  prunifolia.  It 
has  seemed  singular  to  the 
writer  that  a  character  so  gen- 
erally accepted  and  used  to 
separate  definitely  species  and 
groups  of,  species  should  exhibit 
the  degree  of  inconstancy  here 
appearing;  an  occasional  fruit 
or  flower  departing,  even  in 

marked  degree,  from  normal,  is 

,i  ,  ,  FIG.  19. — FRUITING  BRANCH  OF  M,  baccata 

to  be  expected,  as  every  botan-  (807)   SEPTBMBER  i6 

1st  of  experience  knows,  but  Some  of  the  fmits  have  deciduous  calyx 
here  we  have  little  more  than  lobes,  and  in  other  fruits  the  lobes  persist. 


'Regel,  Eduard.    Gartenflora  2,  208.    1853. 


466 


BULLETIN  No.  275 


[June, 


one-third  of  more  than  6,000  individuals  retaining  a  character  sup- 
posed to  be  constant  for  the  species,  while  a  little  less  than  two-thirds 
exhibit  the  direct  opposite,  that  is,  persistent  calyx  lobes. 


FIG.  20. — FRUIT  CLUSTER  OF  M.  baccata   (807),  SEPTEMBER  16 

The   same    characteristic    of    deciduous   and    persistent    calyx 
lobes  is  shown  here  as  in  Fig.  19. 


But  the  finding  regarding  this  character  in  its  relation  to  this 
variety  is  not  an  isolated  case;  at  least  seven  other  species  and  vari- 
eties of  Malus  in  our  fruiting  collection  behave  in  the  same  way ;  they 
bear  fruits  with  regularly  deciduous  calyx  lobes  and  fruits  in  which 
the  lobes  persist  mingled  together  on  the  same  tree  or  even  in  the  same 
cluster.  I  may  add  that  this  mixing  of  fruits  having  deciduous  calyx 
lobes  with  those  having  persistent  lobes  is  not  confined  to  the  supposed 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  467 

wild  or  ornamental  forms,  but  sometimes  occurs  in  some  orchard  vari- 
eties of  M.  mains.  In  Wythe  and  Rome  the  calyx  lobes  are  com- 
monly persistent  as  in  other  varieties,  but  we  have  record  of  16  fruits 
on  one  tree  of  Wythe  and  3  fruits  on  one  tree  of  Rome  in  each  of 
which  the  calyx  lobes  were  deciduous  in  the  same  manner  and  left  the 
same  kind  of  scar  as  in  those  species  or  forms  described  as  having 
regularly  deciduous  calyx  lobes.  Fig.  19  shows  a  fruiting  branch  of  No. 
807  bearing  some  fruits  having  deciduous  calyx  lobes  and  others  in 
which  the  lobes  persist;  the  same  characteristic  is  also  seen  in  the 
single  cluster  appearing  as  Fig.  20.  Core  large,  cordate,  median,  closed 
or  sometimes  half-open;  core  lines  clasping,  cells  axile;  carpels  round- 
ish-elliptical, entire,  glabrous  or  sometimes  tufted,  concave;  seeds 
plump,  of  medium  size  and  brown  color;  flesh  yellowish,  firm,  crisp, 
moderately  juicy,  acid. 

7.  Mains  baccata  var.  (808) 

Represented  only  in  the  800  series  by  one  tree  now  sixteen  years 
old  from  root-graft  made  January  20,  1908,  one  tree  now  ten  years  old 
from  graft  made  in  1914,  and  one  tree  on  dwarf  stock  in  greenhouse, 
now  seven  years  old  from  graft  of  1917.  The  older  tree  now  has  a 
height  of  20%  feet,  a  spread  of  13  feet,  and  a  trunk  diameter  of  7.1 
inches. 

Tree. — The  strictly  erect  habit  of  growth,  very  large  leaves,  and 
smooth,  light  greenish-brown  bark  are  the  chief  characteristics  distin- 
guishing this  form  from  any  other  in  the  collection.  Bark  of  two-  and 
three-year-old  wood  light  brown,  bark  of  new  shoots  green;  all  more 
or  less  roughened  by  the  numerous  round  or  elongated  lenticels.  Over 
the  lower  part  of  the  tree  every  bud  on  wood  of  the  preceding  year 
sends  out  a  leafy  spur  imparting  an  appearance  of  density  to  the  foli- 
age; above,  internodes  are  longer,  the  single  leaves  more  remote,  and 
the  appearance  more  open. 

Leaves. — Leaves  from  the  short  spurs  are  extremely  variable  in 
size  and  shape,  from  small  round  leaves  1  inch  long  to  oblong-elliptical 
leaves  6  inches  long  and  2  inches  wide;  leaves  from  shoots  of  the  cur- 
rent year  are  elliptical,  4  to  7  inches  long  and  2%  inches  wide  termin- 
ating in  long-acuminate  points;  crenate-serrate,  glabrous  both  sides, 
dull  dark  green  above,  light  green  below;  petioles  1%  inches  long, 
stout,  very  slightly  pubescent,  channel  shallow;  texture  thin. 

Flowers. — Produced  in  discontinuous  masses  from  lateral  buds  on 
wood  of  the  preceding  year,  only  a  part  of  such  shoots  flower;  others 
produce  leaves  only,  hence  there  is  not  that  appearance  of  massed 
bloom  that  is  characteristic  of  some  other  forms.  No  flowers  are  pro- 
duced from  spurs  of  interior  or  lower  branches. 

Flower  buds  5  or  6  in  each  cluster,  on  slender  pedicels  25  to  30  mm. 
long,  sparsely  pubescent,  pink,  fading  to  nearly  white  before  anthesis; 


468 


BULLETIN  No.  275 


[June. 


just  before  opening  the  buds  are  oval  in  form,  about  13  mm.  long  by  7 
or  8  mm.  broad.  Flower  expands  30  mm. ;  calyx  lobes  linear,  acute,  8 
mm.  long  by  2  mm.  wide  at  base,  scantily  pubescent  outside,  densely 
pubescent  within;  in  young  buds  the  lobes  are  connivent,  becoming 
erect  and  finally  reflexed  in  open  flowrers.  Petals  obovate,  rounded  at 
apex,  tapering  at  base  to  the  claw,  which  is  2  mm.  in  length ;  stamens 
14  to  18,  filaments  slender,  the  bases  broadened,  6  to  8  mm.  long; 
anthers  plump,  light  yellow;  styles  5,  slender,  somewhat  clavate  at 
apex,  8  mm.  long,  connate  1  mm.  up  from  base,  a  few  hairs  about  the 
point  of  separation;  stigmas  small,  oval,  oblique. 

Fruit. — Roundish-oblate,  vertical 
diameter  25  mm.,  transverse  diameter 
30  mm.,  yellow  with  bronze  blush  on 
side  exposed  to  sun;  pedicels  30  mm. 
long,  slender,  green,  glabrous,  cavity 
moderately  deep,  broad,  obtuse,  regu- 
lar; basin  rather  deep,  broad,  smooth 
or  somewhat  ribbed ;  calyx  tube  short, 
broad,  conical;  calyx  lobes  regularly 
deciduous,  all  falling  before  maturity. 
The  yellow  fruit  and  the  larger  gla- 
brous leaves  are  the  chief  distinctions 
between  this  form  and  the  form  under 
the  number  806. 

8.  Mains  baccata  maxima  (810) 

Represented  only  in  the  800  series. 
The  variety  is  vigorous,  producing 
erect,  symmetrical  trees,  but  has 
proved  so  susceptible  to  blight  that  it 
cannot  be  recommended  for  breeding 
or  for  ornamental  planting.  The  trees 
grafted  in  1908  have  all  been  killed-by 
blight  and  only  four  trees  from  grafts 
made  in  1914  now  remain  to  represent 
the  variety  in  the  collection.  These 
trees  now  in  their  eleventh  year  have 
escaped  disease;  they  average  14  feet 
in  height,  11  in  spread,  and  have  an 
average  trunk  diameter  of  4.3  inches. 
In  the  years  1913  to  1917  the  variety 

was  used  as  female  in  ten  crosses,  seven  of  which  are  now  represented 
by  trees  from  six  to  ten  years  old  in  orchard.  In  the  same  years  it  was 
also  used  as  the  pollen  parent  in  eleven  crosses,  and  seven  of  these 
crosses  are  now  represented  in  orchard.  These  hybrid  trees  have  not 


FIG.    21. — TREE    OF    M.    baccata 
maxima  (810) 

This  photograph  taken  in  Oc- 
tober illustrates  the  vigor  and 
erect  habit  of  the  variety. 


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469 


escaped  blight  entirely  but  have  not  shown  the  susceptibility  to  the 
disease  that  has  developed  in  the  baccata  parent. 

Tree. — The  vigor  and  erect  habit  is  expressed  in  Fig.  21  from  a 
photograph  of  a  perfectly  healthy  tree  as  taken  in  October.   Bark  of 
the     trunk     is     light    yellowish-brown, 
smooth;  bark  of  twigs  is  light  reddish- 
brown;  lenticels  are  few,  small,  mostly 
round,  inconspicuous. 

Leaves. — Those  from  mixed  buds  on 
flowering  shoots  are  small,  1  to  2  inches 
long,  ovate  to  lanceolate,  densely  white 
tomentose;  mature  leaves  are  from  3  to 
5  inches  long,  1  to  2  inches  wide,  ellipti- 
cal, oblong,  or  ovate;  accuminate,  cre- 
nate-serrate,  glabrous  both  sides,  rather 
dull  dark  green  above,  lighter  below, 
smooth,  texture  thin,  limp,  often  droop- 
ing; petioles  slender,  1  to  1%  inches 
long,  glabrous,  narrowly  and  deeply 
channelled,  stipules  small,  linear,  soon 
disappearing. 

Flowers. — Produced  profusely  from 
terminal  and  lateral  buds  of  terminal 
shoots  and  to  some  extent  from  terminal 
buds  of  short  spurs;  buds  light  pink 
when  young,  fading  to  pure  white  before 
opening;  as  they  approach  anthesis  the 
buds  appear  long,  slender,  and  pointed. 
Flowers  expand  from  25  to  30  mm.  Calyx 
lobes  triangular,  pubescent  both  sides; 
petals  oval,  15  mm.  long,  9  mm.  wide, 
rounded  at  apex,  abruptly  rounded  at 
base  to  the  short  but  distinct  claw,  pure 

white;  anthers  plump,  light  yellow;  styles  slender,  9  mm.  long,  connate 
ll/2  mm.  at  base,  copiously  hairy  in  a  band  3  mm.  wide  beginning  1  m. 
from  base  and  extending  above  the  point  of  separation;  stigmas  capi- 
tate, oval.  Fig.  22  showing  a  twig  in  bud  is  from  photograph  taken 
April  21. 

Fruit. — Round  or  slightly  oblate.  Weight,  longitudinal,  and  trans- 
verse diameters  as  determined  from  82  fruits  are  as  follows : 


FIG.  22. — TWIG  OF  M:  baccata 

maxima  (810)  IN  BUD, 

APRIL  21 


Weight 

gms. 

Maximum 1 1 .66 

Minimum 1.34 

Average 8.38 


Longitudinal  diameter 
mm. 

Maximum 25 

Minimum 13 

Average 20 


Transverse  diameter 

mm. 

Maximum 28 

Minimum 16 

Average 23 


470 


BULLETIN  No.  275 


[June, 


Ground  color  yellow  with  blushed  over-color,  usually  light  red, 
but  in  some  much  exposed  fruits  becoming  quite  dark;  on  the  othei 
hand  some  fruits  are  yellow  with  no  more  than  a  pinkish  blush ;  bloom 
scant,  waxy,  white;  skin  smooth,  polished,  tough,  of  medium  thick- 


FIG.  23. — FRUITING  BRANCH  OP  M.  baccata  maxima 
(810),  SEPTEMBER  1 

ness;  dots  few,  small,  regular,  round,  white,  or  sometimes  russet;  cavity 
deep,  medium  to  .broad,  acute,  regular;  stem  slender,  27  to  36  mm. 
long,  green,  somewhat  ribbed,  calyx  lobes  regularly  deciduous;  calyx 
tube  short,  small,  conical,  often  with  projecting  pistil  point. 

9.  Mains  baccata  oblonga  (811) 

Propagation  of  this  form  by  root-grafts  in  1908  was  unsuccessful; 
but  some  of  the  scions  top-worked  on  a  Sops  of  Wine  tree  grew  with 


1926] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


471 


reasonable  vigor.  In  1911  scions  from  this  tree  were  worked  on  both 
paradise  and  Doucin  stocks  in  pots  for  use  in  the  greenhouse.  One 
tree  on  Doucin  stock  survived,  has  fruited  each  spring  since  1913,  and 
tho  still  small,  is  perfectly  healthy.  In  1913  Yellow  Transparent  pollen 
was  used  on  49  flowers;  48  fruits  matured  and  thirty-two  seedlings 
now  ten  years  old  are  living  in  orchard.  In  the  years  1914,  1916,  and 


\ 


FIG.  24. — POTTED  TREE  OF  M.  baccata  oblonga 
(811)  ON  DOUCIN  STOCK 

1917,  seven  other  crosses  were  made  and  forty-six  trees  from  crosses  by 
Akin,  Delicious,  and  the  crab  form  No.  830,  carried  as  M.  mains 
var.  are  now  in  orchard  at  seven  and  nine  years  of  age.  The  variety 
was  used  as  the  male  parent  in  three  crosses  involving  twenty-eight 
pollinations,  but  two  of  the  crosses  failed  and  the  third,  on  Akin,  pro- 
duced only  one  fruit  from  eleven  pollinations.  Only  one  seedling  from 
this  cross  survives;  it  is  seven  years  old.  Crosses  with  this  variety  as 
the  mother  parent  were  more  successful  than  where  it  was  used  as  the 


472 


BULLETIN  No.  275 


[June, 


pollen  parent.  Having  no  tree  upon  its  own  roots  or  upon  a  stock  other 
than  dwarf,  it  is  not  possible  to  give  habit  of  the  variety  as  a  stan- 
dard; from  observation  of  growth  of  top-grafts,  both  on  ordinary 
stocks  and  on  Doucin,  it  appears  that  the  natural  trend  of  branches 
is  obliquely  upward,  giving  a  tree  somewhat  less  erect  than  is  No.  806, 
but  not  inclined  to  spread  as  much  as  does  the  variety  No.  807.  M. 
baccata  oblonga  on  Doucin  stock  as  it  appeared  June  21,  1916,  is 
shown  in  Fig.  24.  The  tree  was  at  that  time  3  feet  high;  at  this  time, 

eight  years  later,  it  measures  5% 
feet  in  height,  2%  feet  in  spread, 
and  has  a  trunk  diameter  of  1% 
inches.  Bark  of  older  wood  light 
gray,  of  new  shoots,  green,  becom- 
ing light  brown  as  they  mature; 
internodes  1%  to  1%  inches  long, 
lenticels  rather  numerous,  mostly 
elongated. 

Leaves. — 3%  to  5%  inches  long, 
ll/2  to  2  inches  wide,  ovate  to  el- 
liptical, lower  mostly  obtusely 
rounded  at  apex,  upper  acuminate, 
irregularly  doubly  serrate,  smooth, 
glabrous  both  sides,  glandular 
along  the  ribs  above,  dark  green 
above,  somewhat  lighter  below; 
texture  thin,  limp;  petioles  stout, 
1*4  to  2%  inches  long,  glabrous; 
stipules  %  to  %  inch  long,  lanceo- 
late, serrate,  inclined  to  persist. 

Flowers. — From  terminal  and 
lateral  buds  on  wood  of  the  pre- 
ceding year;  young  buds  pink, 

fading  to  nearly  white  before  opening;  flowers  expand  32  mm.; 
pedicels  slender,  variable  in  length,  between  19  and  32  mm.,  gla- 
brous; calyx  lobes  narrowly  triangular,  acuminate,  11  mm.  long, 
iy2  mm.  wide  at  base,  glabrous  outside,  pubescent  wyithin;  petals 
5,  oval,  17  mm.  long  by  11  mm.  wide,  rounded  at  apex,  white,  slightly 
tinged  pink,  claw  short  but  distinct,  about  1  mm.  long.  Stamens  16  to 
20,  filaments  slender,  6  to  8  mm.  long;  anthers  small  but  plump,  light 
yellow;  styles  mostly  5,  in  some  flowers  4,  slender,  12  mm.  long,  hairy 
at  base,  somewhat  flattened  at  apex;  stigmas  oval,  oblique.  Twigs  in 
buds  as  photographed  in  greenhouse  February  24,  appear  in  Fig.  25. 

Fruits. — Smaller  than  in  any  other  variety  of  baccata.  Fifty  fruits 
weighed  and  measured  ranged  as  follows: 


FIG.  25. — TWIGS  OF  M.  baccata  ob- 
longa  (811),  PHOTOGRAPHED  IN 
GREENHOUSE,  FEBRUARY  24 


19281 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


473 


Weight 

gms. 

Maximum 2.70 

Minimum 54 

Average 1 .41 


Longitudinal  diameter 
mm. 

Maximum 16 

Minimum 9 

Average . . . 12 


Transverse  diameter 

mm. 

Maximum 16 

Minimum 8 

Average 13 


Notwithstanding  the  fact  that  averages  of  the  two  diameters  indi- 
cate a  round  or  even  slightly  oblate  form,  the  majority  of  fruits  appear 
distinctly  oblong  as  in  Fig.  26;  base  regular,  rounded,  apex  flattened, 
regular  or  in  some  fruits  somewhat  ribbed;  sides  equal.  The  majority 


FIG.  26. — FRUITS  OF  M.  baccata  oblonga  (811) 
The  majority  of  fruits  are  distinctly  oblong. 


of  fruits  are  yellow  with  a  red  blush,  but  some  are  entirely  yellow  and 
others  have  the  yellow  entirely  overlaid  with  red,  which  varies  thru 
light  shades  to  rather  dark;  bloom  scant,  wraxy,  gray;  skin  smooth, 
polished,  tough,  thin;  dots  many,  small,  russet  or  sometimes  white; 
cavity  medium  in  depth  and  breadth,  acute,  regular;  stem  long,  26  to 
45  mm.,  slender,  erect,  green,  glabrous;  basin  shallow,  broad,  obtuse, 
often  slightly  ribbed;  calyx  lobes  uniformly  deciduous;  calyx  tube 
small,  short,  conical;  core  large,  closed;  cells  4  to  6.  Of  29  fruits 
examined  10  had  4  cells  each,  18  had  5  each,  and  1  had  6  cells. 

10.  Mains  baccata  sanguinea  (813) 

Represented  by  three  trees  now  sixteen  years  old  from  root-grafts 
made  in  1908  and  by  several  trees  grafted  in  1912  and  1914.  The  trees 
are  healthy  and  of  reasonable  vigor,  but  have  rather  open  tops  with 


474  BULLETIN  No.  275  [June, 

foliage  less  dense  than  in  a  number  of  other  forms;  this  appearance  of 
openness  is  due  mainly  to  the  preponderance  of  small  leaves.  The 
older  trees  average  22  feet  in  height,  have  an  average  spread  of  23 
feet,  and  a  trunk  diameter  of  7.6  inches.  The  habit  is  somewhat 
spreading,  resembling  807,  but  of  less  vigorous  appearance  because  of 
the  smaller  leaves.  Bark  of  trunk  is  light  grayish-brown ;  of  twigs  dark 
greenish-brown.  Leaves  ll/2  to  5  inches  long,  %  inch  to  2  inches  wide, 
elliptical  or  lanceolate,  some  of  the  smaller  roundish-oblong  or  ovate, 
generally  acute,  but  the  smaller  mostly  obtuse,  crenate-serrate ;  gla- 
brous above,  very  scantily  pubescent  below,  dull  dark  green  above, 
somewhat  lighter  below;  petioles  1  inch  long  varying  from  slender  to 
stout,  slightly  pubescent,  channeled.  Texture  thin,  limp.  Some  leaves 
are  as  large  as  any  on  807,  but  the  proportion  of  small  leaves  is  greater, 
giving  the  general  appearance  of  having  less  foliage.  The  flowers  were 
borne  from  terminal  buds  of  short  spurs;  there  were  none  on  terminal 
shoots  of  the  preceding  year. 

Leaves. — Those  from  mixed  buds  are  small,  ovate,  acute,  serrate, 
scantily  pubescent  below,  and  with  a  few  short  hairs  along  the  midrib 
above,  color  a  medium  green.  Buds  globular,  6  to  7  in  a  cluster,  dark 
pink;  pedicels  slender,  25  mm.  long,  pubescent,  green;  ovaries  green, 
pubescent. 

Flowers. — Expand  30  mm.  Calyx  lobes  5,  triangular  acuminate, 
6  mm.  long,  2  mm.  wide  at  base,  both  sides  closely  pubescent,  green, 
tips  somewhat  reflexed  even  in  bud;  petals  oval  or  nearly  round,  15 
mm.  long  by  13  mm.  broad,  claw  1  mm.  long,  mostly  pale  pink,  but 
with  darker  pink  in  spots  on  the  outside,  especially  about  the  base; 
stamens  20,  filaments  slender,  5  to  8  mm.  long,  anthers  plump,  light 
yellow.  Styles  5,  slender,  10  mm.  long,  tips  flattened  and  surmounted 
by  the  irregularly  oval,  oblique  stigmas,  connate  1%  mm.  at  base,  gla- 
brous at  base,  but  hairy  about  the  point  of  separation  and  continuing  a 
short  distance  above.  The  hairs  are  shorter  and  less  numerous  than  in 
some  other  forms. 

Fruits. — Roundish,  many  of  them  appearing  to  the  eye  as  dis- 
tinctly oblong,  but  in  every  specimen  measured  the  transverse  diam- 
eter exceeds  the  longitudinal  diameter  from  3  to  9  mm.,  which  points  to 
oblate  as  a  proper  designation  of  form.  Averages  of  weight  and  size  as 
determined  from  179  fruits  are:  weight  35.32  grams;  long  diameter 
39  mm.;  transverse  diameter  44  mm.  Base  regular,  rounded;  apex 
irregular,  ribbed,  cross-section  irregularly  ribbed,  sides  equal.  Color  a 
clear  yellow  which  darkens  to  nearly  orange  where  exposed  to  direct 
sunlight;  immature  and  shaded  fruits  are  greenish-yellow  or  sometimes 
whitish-yellow;  red  appears  to  be  entirely  wanting;  bloom  scanty, 
scarcely  perceptible;  skin  smooth,  polished,  thin,  tough;  dots  few, 
small,  round,  white,  scattered,  inconspicuous.  Cavity  medium  in  depth 
to  deep,  rather  narrow,  acuminate,  regular;  stem  slender,  21  to  25  mm. 


1926] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


475 


in  length,  clavate,  erect  or  often  oblique,  green,  scantily  pubescent. 
Calyx  small,  pubescent,  closed.  Basin  shallow  to  medium  in  depth, 
rather  narrow,  obtuse,  irregular,  ribbed;  calyx  lobes  small,  rather 
shortly  acute,  sometimes  reflexed,  sometimes  connivent;  calyx  tube 
small,  short,  conical.  Core  of  medium  size,  cordate,  oblate,  distant, 
closed,  stamens  marginal,  core  lines  clasping.  Cells  axile,  of  uniform 
size;  carpels  are  mostly  obovate,  but  in  some  fruits  ovate,  commonly 
entire,  but  often  emarginate,  glabrous,  moderately  concave.  Seeds 
plump  of  medium  size,  short  and  broad  in  form,  medium  brown  in 
color.  In  1917,  after  a  cool,  wet  summer  the  fruits  began  ripening  and 


FIG.  27. — FRUITS  OF  M.  baccata  sanguined  (813)    NATURAL  SIZE 

falling  about  the  first  of  September.  Doubtless  a  hot  summer  would 
bring  them  to  maturity  a  week  or  two  earlier.  In  seed  production  the 
fruits  of  this  form  of  Malus  far  exceed  those  of  any  other  crab  form 
examined.  The  179  fruits  analyzed  bore  1,563  seeds,  an  average  of  8.73 
to  each  fruit;  this  is  more  than  double  the  average  for  the  crab  group, 
while  only  about  one-third  of  the  orchard  varieties,  for  which  record 
has  been  made,  equal  or  exceed  this  average.  The  range  in  seeds  to 
each  fruit  is  from  6  to  11  and  the  distribution  is  as  follows;  with  6 
seeds  each  7,  with  7  each  17,  with  8  each  38,  with  9  each  74,  with  10 
each  41,  and  with  11  each  2.  Flesh  of  the  fruit  is  white,  firm,  crisp, 
moderately  juicy,  subacid,  and  of  agreeable  flavor.  That  this  form  of 
Malus  appears  under  a  name  that  does  not  belong  to  it  is  evident  from 


476  BULLETIN  No.  275  [June, 

its  character;  its  affinities  do  not  lie  with  M.  baccata,  as  is  shown  by 
the  regularly  persistent  calyx  lobes  and  the  relatively  short  pedicels, 
and  certainly  there  is  nothing  to  suggest  sanguined  as  a  varietal  name. 
In  habit  of  growth  and  foliage  it  suggests  M.  prunifolia,  but  the 
fruit  is  widely  different  from  that  of  any  of  the  forms  of  prunifolia 
now  in  the  collection.  Definite  determination  of  its  proper  systematic 
position  cannot  be  made  at  this  time.  A  fruiting  branch  as  photo- 
graphed, natural  size,  is  shown  in  Fig.  27.  This  form  has  been  used  in 
only  one  cross;  flowers  pollinated  by  Collins  in  1917  yielded  84  fruits 
representing  over  57  percent  of  the  pollinations.  From  seeds  of  these 
fruits  there  are  in  orchard  287  seedlings,  now  in  their  seventh  year; 
none  have  yet  fruited. 

11.  Mains  baccata  sieboldi  (814) 

Only  one  of  ten  root-grafts  made  in  1908  has  survived;  this  is  now 
at  sixteen  years  of  age,  14  feet  high,  has  a  spread  of  13  feet,  and  a 
trunk  diameter  of  4.1  inches.  Branches  are  ascending,  forming  a  fairly 
symmetrical  crown;  bark  of  trunk  and  branches  light  grayish-brown, 
twigs  of  the  current  year  green. 

Leaves. — Two  to  4%  inches  long,  %  to  2  inches  broad,  elliptical 
or  oval,  accuminate  or  acute,  crenate-serrate,  glabrous  both  sides,  light 
green  above,  still  lighter  below;  petioles  stout,  %  to  1  inch  long,  gla- 
brous, stipules  lanceolate,  entire,  petiolate,  persisting. 

Flowers. — Produced  from  terminal  and  lateral  buds  of  terminal 
shoots  and  from  terminal  buds  of  short  spurs.  Pedicels  slender,  green, 
1  inch  long,  glabrous;  ovary  green,  glabrous.  Calyx  lobes  5,  triangular 
acuminate,  6  mm.  long  and  2  mm.  wide  at  base,  glabrous  without, 
closely  and  finely  pubescent  within.  Flower  expands  28  mm.  Buds 
light  pink  fading  to  pure  white  as  flowers  open ;  petals  oblong  or  nearly 
orbicular,  12  mm.  long  by  10  to  11  mm.  wide,  rounded  at  apex  and 
base,  claw  very  short.  Stamens  18,  filaments  slender,  5  to  8  mm.  long, 
anthers  plump,  light  yellow.  Styles  5,  slender,  11  mm.  long,  connate 
from  base  for  2%  mm.,  glabrous  for  1%  mm.,  and  then  hairy  to  just 
above  the  point  of  separation.  Stigmas  oval,  oblique. 

Fruit. — Small,  round  or  roundish,  yellow  with  bronze  blush  in  the 
sun;  cavity  shallow,  broad,  basin  a  very  slight  depression  within  the 
limits  of  the  circular  russet  scar  left  by  the  deciduous  calyx  lobes; 
pedicels  slender,  12  to  20  mm.  long,  green,  glabrous.  (Fig.  28.) 

This  variety  of  M.  baccata  has  been  used  as  female  in  three 
crosses.  In  1913,  pollen  of  Fanny  was  used  on  13  flowers;  the  at- 
tempted cross  failed.  In  1916  from  flowers  pollinated  by  Oldenburg 
100  fruits  matured;  these  represented  about  28  percent  of  the  pollina- 
tions ;  from  these  fruits  279  seedlings  were  planted  in  nursery  and  in 
1924,  the  eighth  year,  218  are  living  and  are  rated  as  65  percent 
"good,"  22  percent  "fair,"  and  12  percent  "poor."  The  largest  tree  is  10 


19261 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


477 


feet  3  inches  high,  has  a  spread  of  7  feet  3  inches  and  a  trunk  diameter 
of  2%  inches;  the  smallest  tree  is  8  inches  high,  has  no  spread,  and  a 
diameter  of  only  .2  inch.  The  average  is  a  tree  6  feet  high  with  spread 
of  3%  feet,  and  a  trunk  diameter  of  1.3  inches.  Forty-nine  of  the 
trees  began  flowering  this  season  (1924)  and  some  of  these  are  matur- 
ing fruits.  In  1917  Longfield  pollen  was  used  on  96  flowers;  the  pollin- 


FIG.  28. — FRUITS  OF  M.  baccata  sieboldi  (814) 
These  fruits  are  small,  round,  and  yellow,  showing  a  bronze 
blush  in  the  sun. 


ations  were  12%  percent  successful  and  from  these  fruits  there  are  in 
orchard  fifteen  trees  now  in  their  seventh  year;  none  of  these  have 
flowered.  The  rating  of  the  trees  is  fourteen  "good,"  and  one  "fair." 
Height  ranges  between  4  and  8  feet  with  an  average  of  5%  feet;  the 
average  spread  is  4  feet  and  the  average  diameter  1.3  inches. 

This  variety  was  used  as  the  pollen  parent  in  four  crosses,  all  in 
the  year  1914.  On  Ben  Davis  the  pollinations  were  10  percent  suc- 
cessful; on  Shackleford  32  percent  successful;  on  Winesap  6  percent 


478  BULLETIN  No.  275  [June, 

successful ;  on  Black  Ben  Davis  one  fruit  matured  from  48  pollinations 
but  the  fruit  contained  no  viable  seeds.  From  the  three  other  crosses 
there  are  in  orchard  eleven  trees  of  the  Ben  Davis  cross,  twenty-five 
of  the  Shackleford,  and  nine  of  the  Winesap  cross.  The  seed  content 
of  fruits  from  these  crosses  was  good,  averaging  7  to  each  fruit;  germ- 
ination averaged  60  percent,  but  in  each  group  there  was  a  large  pro- 
portion of  weak  seedlings  that  died  at  intervals  until  the  trees  remain- 
ing represent  only  44  percent  of  the  germinations.  The  trees  living 
have  each  year  improved  in  grade  until  nearly  all  now  rank  as  good. 
Four  of  the  nine  Winesap,  twelve  of  twenty-five  Shackleford,  and 
eight  of  eleven  Ben  Davis  have  fruited.  Fruits  are  all  crab-like,  inter- 
mediate in  size  between  fruits  of  parents,  but  always  nearer  the  crab- 
parent. 

12.  Mains  cashmerica 

Scions  of  this  form  were  received  in  each  of  the  three  series.  With 
the  scions  received  in  1907  under  the  number  19640  was  this  note 
appearing  in  the  list,  "is  a  Himalayan  species.  It  is  growing  well  at 
the  Arnold  Arboretum  and  is  interesting  as  one  of  the  few  Himalayan 
trees  that  flourish  in  that  climate."  Root-grafts  were  made  but  none 
lived.  Scions  received  in  1908  were  grafted  both  as  root-grafts  and 
top-grafts,  but  again  all  failed. 

Scions  received  in  1912  were  worked  as  root-grafts  and  also  as 
top-grafts  on  paradise  and  Doucin  stocks  in  pots.  A  number  of  these 
grafts  succeeded  and  there  are  in  orchard  four  root-grafted  trees,  now 
in  their  thirteenth  year.  For  use  in  the  greenhouse  are  three  trees  on 
dwarf  stocks;  these  are  now  eleven  years  old. 

The  four  trees  in  orchard  are  healthy  vigorous  trees  that  have 
never  been  attacked  by  blight;  they  are  upright,  approaching  pyra- 
midal in  form;  average  height  is  22  feet,  spread  14  feet,  and  trunk 
diameter  7.07  inches.  Bark  of  older  wood  light  gray,  of  young  twigs 
reddish-brown;  lenticels  few,  small,  round,  light  russet. 

Leaves  rather  small,  1%  to  3%  inches  long,  by  Y2  to  1%  inches 
wide,  oval  or  elliptical,  acute,  serrate;  some  of  the  upper  leaves  on 
new  shoots  are  three-lobed ;  all  are  glabrous  above  and  scantily  pubes- 
cent below;  light  green,  the  lower  surface  only  slightly  lighter  than 
the  upper;  petioles  %  to  1%  inches  long,  slender,  pubescent,  red; 
stipules  short,  lanceolate,  serrate,  petiolate. 

Flowers. — Buds  are  deep  red,  fading  to  pink  as  flowers  are  ready 
to  open,  oval,  becoming  somewhat  elongated;  flower  expands  23  mm.; 
pedicels  rather  stout,  18  mm.  long,  pubescent;  calyx  lobes  triangular, 
acuminate,  pubescent  both  sides,  4  mm.  long,  erect  in  bud,  becoming 
horizontal  in  open  flowers;  petals  5,  oval,  12  mm.  long  by  6  mm.  wide, 
claw  short,  apex  rounded,  white  with  irregular  pink  areas;  stamens  in 
flower  examined,  15,  filaments  slender,  4  to  6  mm.  long,  anthers  plump, 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


479 


light  yellow;  styles  5,  slender,  9  mm.  long,  distinct  nearly  to  the  base, 
pubescent  in  a  band  about  the  point  of  separation,  stigmas  capitate, 
irregularly  round. 

Fruits. — Round  or  slightly  oblate,  base  irregular,  flat,  apex  irregu- 
lar, slightly  conical,  ribbed  in  cross-section,  sides  equal.  Six  fruits 
examined  average  17  mm.  in  vertical  diameter,  19  mm.  in  transverse 
diameter,  and  have  an  average  weight  of  2.33  grams.  Color  orange- 
yellow,  bloom  scanty,  waxy,  white;  skin  smooth,  thin,  tough;  dots  few, 
of  medium  size,  round,  white,  scattered,  inconspicuous;  cavity  shallow, 
broad,  obtuse;  stem  slender,  11  to  25  mm.  in  length,  erect,  smooth, 


FIG.  29. — FRUIT  OF  M .  cashmerica  (1207),  NATURAL  SIZE 


green  more  or  less  streaked  with  red.  Calyx  lobes  deciduous  in  5 
fruits,  persistent  in  1,  lobes  are  of  medium  size,  rather  short  and  broad, 
acute,  erect.  Basin,  in  those  fruits  having  deciduous  lobes,  shallow, 
moderately  broad,  obtuse,  irregularly  ribbed;  the  fruit  with  persistent 
lobes  has  no  basin;  bases  of  the  lobes  are  fleshy  and  the  tips  connivent; 
calyx  tube  short,  small,  conical.  Core  of  medium  size,  cordate,  median, 
closed;  stamens  marginal,  core  lines  clasping,  cells  uniform,  axile; 
carpels  elliptical,  glabrous,  moderately  concave ;  seeds  of  medium  size, 
plump,  light  brown.  Flesh  yellow,  firm,  crisp,  juicy,  acid,  astringent. 
Five  of  the  fruits  appear,  natural  size,  in  Fig.  29. 


480  BULLETIN  No.  275  Uune, 

With  M.  cashmerica  as  the  female  parent  three  crosses  were 
made  in  the  greenhouse  in  1917;  these  crosses  were  by  Fanny  with 
four  pollinations  yielding  four  fruits;  by  Jonathan  with  twenty-one 
pollinations,  yielding  twenty-one  fruits,  and  by  Delicious  with  twenty- 
two  pollinations  yielding  ten  fruits.  The  three  crosses  are  now  repre- 
sented in  orchard  by  four  seedlings  from  the  Fanny  cross,  sixty-four 
from  the  Jonathan  cross,  and  nineteen  from  the  Delicious  cross.  These 
seedlings  have  grown  with  reasonable  vigor,  but  none  have  yet 
flowered.  The  same  season  pollen  of  M.  cashmerica  was  used  in  four 
crosses;  eight  pollinations  on  Delicious  and  nine  on  Grimes  failed; 
eight  pollinations  on  Grimes  yielded  1  fruit  from  which  four  seedlings 
are  growing,  and  nineteen  pollinations  on  Jonathan  matured  5  fruits 
from  which  twenty-three  seedlings  are  in  orchard.  As  the  female  par- 
ent pollinations  were  nearly  75  percent  successful,  but  used  as  male 
the  success  percentage  was  a  little  less  than  14  percent.  Additional 
crosses  may  give  quite  different  results,  but  the  success  when  used  as 
the  mother  commends  the  species  as  a  good  breeder. 

13.  Mains  crataegifolia  (817) 

Scions  of  this  species  were  received  in  each  of  the  three  series. 
With  the  scions  received  in  1907  as  No.  19632  was  this  note,  "some- 
times called  Cormus,  is  a  rare  Italian  tree."  Three  root-grafts  made  in 
1907  failed.  Scions  received  in  1908  were  propagated  under  the  num- 
ber 817,  only  two  of  the  grafts  lived;  one  of  these  died  in  1910,  the 
other  in  1911.  Scions  received  in  1912  were  grafted,  in  part  on  para- 
dise and  in  part  on  ordinary  apple  stocks,  but  none  survived  beyond 
the  second  year.  The  only  representation  of  the  species  now  living  is  a 
small  tree  on  paradise  propagated  in  1911  from  one  of  the  root-grafted 
trees  of  1908.  This  species  does  not  seem  adapted  to  any  of  the  stocks 
upon  which  we  have  attempted  to  propagate  it  and  doubtless  will  soon 
pass  out  of  the  collection.  The  plants  grown  have  red  twigs  and  small 
leaves  that  resemble  those  of  species  of  crataegus. 

Leaves  mostly  1%  inches  long,  ovate  in  outline,  variously  lobed 
and  indented,  the  ultimate  teeth  sharp-pointed,  glabrous  above,  pubes- 
cent below;  yellowish-green;  probably  not  normal  in  either  color  or 
size;  petioles  %  mcn  long,  stout,  pubescent. 

14.  Mains  coronaria  (L)  Mill. 

Pyrus  coronaria  Linnaeus  Spec.,  ed.  1,  480.    1753. 
Mains  coronaria  Miller's  Dictionary,  ed.  8,    2.     1768. 

Scions  received  under  the  number  19641  in  1907  were  worked  as 
both  root-  and  top-grafts,  but  none  lived.  Scions  received  in  1908  and 
worked  as  root-grafts  on  apple  seedling  stocks  also  failed  to  grow.  On 
April  4  of  that  year  seventeen  scions  were  top-grafted  on  a  Sops  of 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


481 


Wine  as  stock;  thirteen  of  the  scions  lived  and  grew  vigorously.  These 
grafts  continued  growth,  forming  a  spreading  crown.  Late  in  the  win- 
ter of  1913  the  tree  was  moved  to  another  area  and  that  spring 
flowered  profusely;  late  in  the  summer  the  trunk  of  the  stock  was 
attacked  by  blight  and  the  tree  died  early  in  the  summer  of  1914. 
Scions  worked  on  paradise  stocks  in  1910  died  during  the  summer  of 

1911.  Early  in  1911  scions  were  top-grafted  on  potted  Doucin  stock; 
these  grew;  the  tree  was 

plunged  in  open  ground 
each  summer  and  forced 
under  glass  each  winter. 
The  tree  flowered  spar- 
ingly in  1914  and  more 
abundantly  in  succeeding 
seasons. 

In  1912,  a  number  of 
root-grafts  were  made,  us- 
ing scions  from  the  top- 
grafted  tree  and  apple 
seedlings  as  stocks;  ten  of 
these  grafts  lived  thru 

1912,  but  only  four  lived 
to  be  planted  in  orchard 
in  1914;  these  made  feeble 
growth   during  the   three 
following  seasons  and 
then  died.  With  the  single 
exception    of    the    scions 
top-grafted    on    Sops    of 
Wine  in  1908,  all  of  the 


FIG.  30. — TREE  OF  M.  coronaria   (818)   IN  POT 

ON  DOUCIN  STOCK 

This  tree  was  from  graft  of  February  24, 
1911,  and  was  21  inches  high  when  photo- 
graphed June  21,  1916. 


grafts  made  very  feeble 
and  unsatisfactory  growth. 
As  an  example  attention 

is  called  to  Fig.  30  from  a  photograph  made  June  21,  1916,  of  the  tree 
from  graft  of  February  24,  1911,  on  potted  Doucin  stock.  The  tree 
when  photographed  was  21  inches  high;  the  annual  increment  increased 
each  year,  but  was  very  small  for  all  years.  In  1915  a  branch  14  inches 
long  terminating  in  a  fruit  bud  was  thrown  out;  in  March,  1916,  this 
terminal  bud,  together  with  several  lateral  buds  on  the  same  branch 
and  one  short  spur  just  above  the  union,  put  forth  flowers;  these  were 
emasculated  and  in  due  time  pollinated;  3  fruits  resulted.  From  an 
upper  lateral  bud  an  extension  branch  over  10  inches  long  has  grown 
and  from  the  main  stem  is  another  shoot  6  inches  long  ;  these  extensions 
are  for  the  sixth  year  in  the  life  of  the  plant  and  indicate  additional 


482  BULLETIN  No.  275  [June, 

vigor,  rather  than  that  the  spring  flowering  was  a  dying  effort.  This  is 
not  a  case  of  scion  over-growing  the  stock,  for  there  is  no  enlargement 
about  the  union,  which  is  fairly  smooth;  nor  does  it  appear  that  the 
stock  is  of  too  rapid  growth,  for  its  diameter  has  increased  by  very 
small  increments.  That  there  is  tolerance  between  stock  and  scion  is 
evidenced  by  endurance  of  life,  but  that  they  are  congenial  is  denied 
by  the  feeble  growth.  Considering  the  experience  with  all  the  grafts  it 
appears  that  M.  coronaria  rejects  the  paradise  and  roots  of  mongrel 
seedlings  as  stocks,  accepts  the  Doucin  with  reluctance,  and  is  most  at 
home  on  the  branches  of  a  free-growing  orchard  variety.  The  breeding 
collection  contains  no  tree  of  normal  growth,  but  campus  specimens 
indicate  an  open,  wide-spreading  top,  with  rigid  branches. 

Leaves. — Variable;  the  most  common  form  is  broadly  ovate, 
rounded,  subcordate  at  base,  obtuse  at  apex,  3  to  3%  inches  long  by 
2%  to  3  inches  wide,  irregularly  incisely  serrate,  or  occasionally  more 
or  less  lobed;  other  leaves  are  oval,  pbovate,  or  some  of  the  smaller 
nearly  orbicular  in  outline,  tapering  somewhat  abruptly  at  base;  apex 
either  rounded  or  in  some  leaves  acute.  All  leaves  are  glabrous  above, 
scantily  pubescent  below;  petioles  short,  %  to  1  inch  long,  stout,  pu- 
bescent, channel  deep  and  very  narrow,  reddish-brown.  Early  in  the 
season  the  leaves  are  bright  green;  later  they  become  dull  dark  green 
or  even  brownish,  the  lower  surface  somewhat  lighter  grayish-green. 

Flowers. — Produced  from  terminal  and  lateral  buds  on  shoots  of 
the  preceding  year,  and  from  terminal  buds  of  short  rigid  spurs;  5  or  6 
flowers  and  from  4  to  7  small  leaves  from  each  mixed  bud.  The  species 
is  peculiar  in  its  inflorescence  in  that  the  bud  axis  elongates,  often  to 
iy2  inches  in  length,  thus  approximating  a  raceme.  In  the  lateral  clus- 
ter taken  for  description  the  axis  is  1  %  inches  long ;  the  2  lower  leaves 
are  separated  by  %  inch  and  show  nothing  in  the  axils,  the  third  leaf 
has,  in  the  axil,  a  small  leafy  shoot  with  2  leaves;  the  fourth  and  fifth 
leaves  each  have  a  flower  pedicel  in  the  axil  and  the  points  of  insertion 
are  separated  %  inch;  %  inch  above  the  last  leaf  is  another  pedicel 
and  about  %  inch  above  this  is  the  final  division  into  2  pedicels;  from 
the  insertion  of  the  lowest  of  the  5  pedicels  to  the  point  of  final  divi- 
sion is  %  inch.  Fig.  31  is  a  bud  cluster  showing  elongation  of  axis. 

Buds  are,  at  first,  globular,  becoming  oval  or  obovate  as  they 
approach  anthesis,  bright  pink,  fading  to  very  light  pink  before  open- 
ing. Flowers  expand  1%  to  iy2  inches.  Pedicels,  the  lower  1%  inches 
long,  upper  1%  inches  long,  slender,  pubescent,  each  bearing  2  linear, 
attenuated  brown  bracts;  upper  part  of  ovary  and  outer  surface  of 
calyx  lobes  glabrous.  Calyx  lobes  5,  triangular,  acute,  4  mm.  long, 
pubescent  on  margins  and  inner  surface;  petals  5,  imbricated  above, 
but  not  below;  when  fully  expanded  they  are  projected  out  so  far  by 
the  long  slender  claws  that  there  is  no  imbrication,  each  petal  stands 
distinct  by  itself;  obovate  or  nearly  orbicular  in  outline,  12  mm.  long 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


483 


by  9  mm.  wide,  pink,  little  lighter  than  when  in  bud,  but  eventually 
fading  to  nearly  white.  Stamens  20,  filaments  slender,  but  short,  5  to 
8  mm.  long;  anthers  large,  of  long  form  and  mostly  tapering  to  an 
acute  point,  light  red.  When  anthers  dehisce  the  pollen  inclines  to 
cling  to  anthers  and  such  as  is  separated  remains  in  masses;  styles  5, 
slender,  10  mm.  long,  light  red,  connate  one-third  the  length,  hairy 


FIG.  31. — BUD  CLUSTER  OF  M.  coronaria  (818),  MARCH  11,  SHOWING 

ELONGATION  OF  Axis.  FIG.  32. — TWIG  IN  BUD,  MARCH  15 
This  species  is  late  flowering,  the  buds  developing  with  less  rapidity 
than  in  most  other  forms  of  Mains. 


with  long,  white,  massed  hairs  from  base  to  just  above  the  point  of 
separation.  Buds  develop  with  less  rapidity  than  in  most  other  forms 
of  Malus  and  the  species  is  late  in  flowering.  Fig.  32  is  a  branch  in 
bud  as  photographed  March  15. 

Fruit. — Records  include  only  5  specimens  developed  from  hand 
pollinations  in  the  greenhouse,  2  in  1914  and  3  in  1916.  These  fruits 
range  in  weight  from  38%  grams  to  54%  grams  with  an  average  of 
44.6  grams ;  in  vertical  diameter  from  34  to  41  mm.  with  an  average  of 
37  mm.  and  in  transverse  diameter  from  37  to  53  mm.  with  an  average 
of  47  mm.  Form  distinctly  oblate,  sides  equal,  base  irregular,  rounded, 
apex  irregular,  flat,  cross-section  ribbed,  dark  green;  bloom  heavy, 
waxy,  gray;  skin  smooth,  unctuous,  thick,  tough;  dots  few,  mostly 
about  the  apex,  medium  in  size,  round,  white,  inconspicuous;  cavity 
shallow,  medium  in  width,  obtuse,  regular;  stem  varying  in  length 
from  40  to  54  mm.,  slender,  erect,  green,  smooth;  basin  deep,  moder- 
ately broad,  acute,  irregular,  ridged.  Calyx  closed,  lobes  of  medium 
size,  long-slender,  acuminate,  erect,  separated;  calyx  tube  large, 
cylindrical.  Core  of  medium  size,  oblate,  median,  closed;  stamens  me- 


484 


BULLETIN  No.  275 


[June, 


dian;  cells  axile,  uniform;  carpels  elliptical,  emarginate,  glabrous,  con- 
cave; seeds  large,  plump,  dark  brown.  Flesh  white,  firm,  crisp,  juicy, 
very  acid,  very  fragrant.  Two  fruits  as  photographed  September  28 
are  shown  in  Fig.  33. 


FIG.  33.- 


-FRUITS  OF  M.  coronaria  (818)  PHOTOGRAPHED  SEPTEMBER  28, 
NATURAL  SIZE 


Opinions  regarding  the  fragrance  and  the  economic  value  of  the 
fruit  are  various.  According  to  Miller's  Dictionary,1  "The  fruit  is 
small,  sour,  and  unfit  for  anything  but  to  make  vinegar  of.  It  lies 
under  the  trees  all  winter,  acquires  a  yellow  color  and  seldom  begins  to 
rot  until  spring  comes  on."  Pursh2  says:  "The  Sweet-scented  Crab- 
tree  the  fruit  of  which  is  well  known  as  a  most  excellent  preserve  for 
the  table,  is  a  very  fine  ornamental  tree,  not  only  for  the  beauty,  but 
particularly  for  the  fine  violet-scent  of  its  flowers."  In  Edwards'  Bot- 
anical Register,3  this  characterization  is  given:  ".  .  .  The  crab  or  apple 
is  small,  yellowish-green,  austere,  with  a  strong  disagreeable  smell;  is 
used  in  confectionery  and  where  abundant  is  sometimes  made  by  the 


"Miller's  Dictionary  2,  part  1.     1807. 
2Pursh,  Frederick.     Fl.  Amer.  Sept.  1,  340. 
'Edwards.    Bot.  Reg.  8,  651.    1882. 


1814. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  485 

American  farmers  into  tolerable  cider.  .  .  .  Introduced  (in  Eng- 
land) by  Mr.  Robert  Furber  in  1724."  Dr.  Sargent4  says  in  describing 
the  fruit,  "deliciously  fragrant."  The  writer  recalls  boyhood  experi- 
ence with  the  extreme  acidity  and  utter  unpalatable  condition  of  the 
fruit  as  found  in  forest  glades  in  late  autumn,  and  also  remembers  the 
characteristic  fragrance  which  was  as  much  appreciated  as  was  that  of 
the  flowers  in  the  late  spring.  Several  writers  on  the  breeding  of  ap- 
ples have  suggested  use  of  the  native  crabs  as  starting  points  in  breed- 
ing work,  but  I  have  been  unable  to  find  any  record  of  actual  breeding, 
or  reports  of  the  performance  of  native  crabs  when  used  as  parent 
plants.  If  there  is  any  virtue  in  our  native  crabs  for  breeding  pur- 
poses, the  degree  of  utility  should  be  ascertained  and  this  is  possible 
only  by  actual  use  of  the  various  forms  as  parents  in  crosses.  Effort 
has  been  made  at  this  Station  to  test  the  native  forms  as  well  as  estab- 
lished varieties  and  foreign  forms  of  the  genus. 

M.  coronaria  has  not  been  represented  by  flowering  trees  in 
orchard,  but  one  dwarf  has  flowered  in  the  greenhouse  and  it  has  been 
used  in  crosses  both  as  female  and  as  male.  As  the  female  parent, 
flowers  pollinated  by  pollen  of  Yellow  Transparent,  Stayman  Winesap, 
Akin,  and  Twenty  Ounce  failed  in  production  of  fruit;  a  1914  cross  by 
Oldenburg  matured  2  fruits  from  twTenty-five  pollinations,  these  fruits 
contained  7  seeds,  2  of  which  germinated  but  were  too  weak  to  live 
and  promptly  died.  In  1916,  14  flowers  pollinated  by  Delicious  ma- 
tured 3  fruits  which  contained  9  seeds;  3  of  the  seeds  germinated 
and  two  seedlings  are  living  in  this  their  eighth  year;  one  is  2  feet  high, 
the  other  9  inches  high,  and  both  are  graded  as  "poor."  In  1917  an- 
other cross  involving  15  flowers  pollinated  by  Jonathan  was  made; 
this  yielded  5  fruits  containing  13  seeds,  7  of  which  germinated ;  three 
seedlings,  now  in  their  seventh  year,  are  living;  they  have  an  average 
height  of  1  foot  10  inches,  and  an  average  diameter  of  .33  inch ;  one  is 
graded  "fair,"  and  two  as  "poor."  Thus  the  net  result  of  pollination 
of  74  flowers  in  seven  crosses  having  M.  coronaria  as  the  female 
parent  is  five  seedlings  seven  and  eight  years  old,  four  of  which  will 
certainly  die  within  the  year  and  the  fifth  is  too  feeble  to  encourage 
the  hope  that  it  may  live  to  fruiting. 

Pollen  of  M.  coronaria  wras  used  in  seven  crosses  as  follows: 
on  Yellow  Transparent,  Akin,  Winesap,  Stayman  Winesap,  Malus 
Soulardi,  Grimes,  and  Twenty  Ounce;  the  first  five  failed  entirely; 
Twenty  Ounce  from  six  pollinations  matured  1  fruit,  but  this  fruit  was 
seedless.  Two  pollinations  on  Grimes  matured  1  fruit  which  contained 
2  seeds,  both  of  which  germinated ;  one  seedling  was  planted  in  nursery 
and  is  now  living  in  orchard  in  its  eighth  year.  It  is  a  fairly  vigorous 
tree  and  grades  as  "good,"  it  is  5  feet  7  inches  high,  has  a  spread  of  5 


4Sargent,  C.  S.    Silva  N.  Amer,  4,  71.     1892. 


486  BULLETIN  No.  275  [June, 

feet  and  a  trunk  diameter  of  1  inch.  Appearance  of  this  tree  warrants 
the  prediction  that  it  will  live  to  produce  fruit.  It  is  the  one  thing  that 
saves  M.  coronaria  from  total  failure  as  a  parent  in  breeding. 

15.  Mains  dioica  (819) 

Malus  non  florens,  fructificans  tamen  Bauhin  Pin.,  435.    1671. 

Pyrus  apetala  Munch.  Hausv.  5,  247.    1771. 

Pyrus  dioica  Moench  Verz.  87.    1785. 

Pyrus  dioica  Linnaeus  Spec.,  ed.  5,  Willdenow  Spec.,  1018.    1797. 

Pyrus  dioica  Miller's  Dictionary,  ed.  9,  2.    1807. 

Malus  dioica  Audibert  Cat. 

Description  as  given  in  Miller's  Dictionary1  is  as  follows: 
"Leaves  oval,  serrate,  flowers  solitary  dioecious,  petals  linear  the 
length  of  the  calyx.  It  is  supposed  that  this  may  have  sprung  from 
the  common  apple.  The  leaves  are  pubescent  underneath.  Peduncles 
one-flowered  at  the  axils  of  the  leaves  towards  the  end  of  the  branches, 
forming  a  sort  of  umbel.  Petals  yellowish-green.  Styles  five,  filiform, 
smooth;  with  club-shaped  stigmas.  Willdenow  did  not  observe  any 
stamens." 

J.  C.  Loudon2  records  the  species  as  below: 

"P.  (M.)  dioica  W.    The  dioecious-sezed  Apple  Tree. 

"Identification.  Willd.  Arb.,  263;  Spec.,  5.  p.  1018.;  Dec.  Prod.,  2.  p.  635.; 
Don's  Mill.,  2.  p.  646. 

"Synonymes.  P.  apetala  Munch.  Hausv.,  5.  p.  247.,  on  the  authority  of 
Willdenow;  Malus  dioica  Audib.  Cat." 

"Leaves  oval,  serrated,  tomentose  beneath.  Flowers,  in  many  in- 
stances solitary.  Sexes  dioecious  by  defect.  Calyx  tomentose.  Petals 
linear,  the  length  of  the  sepals.  Styles  glabrous  (Dec. Prod. II.,  p.  635). 
Cultivated  occasionally  in  gardens  on  the  Continent;  but  we  have  not 
seen  it  in  Britain." 

The  references  to  this  species  that  have  thus  far  been  found 
are: 

Index  Kewensis  2,  669.    1895. 

Pyrus  dioica,  Moench  Verz.  87.  (1785)  —Pyrus  malus. 

From  these  it  appears  that  this  pistillate  form  of  apple  has 
been  known  at  least  as  far  back  as  the  seventeenth  century.  Mar- 
tyn  (1807)  supposes  it  to  be  derived  from  the  common  apple,  and  the 
"Index  Kewensis"  rates  it  as  a  synonym  of  Pyrus  (Malus)  malus.  No 
staminate  form  is  mentioned  and  in  all  probability  there  is  none.  It  is 
not  a  truly  dioecious  form,  but  dioecious  by  defect,  as  is  pointed  out  by 
Loudon.  The  stamens  are  entirely  wanting,  making  this  a  pistillate 
form  in  the  same  manner  as  certain  varieties  of  strawberries  are  pis- 
tillate. The  leaves  and  fruit  suggest  the  common  apple  and  it  may  be 
readily  accepted  as  a  form  of  Malus  malus. 


'Miller's  Dictionary  2,  part  1.    1807. 

2Loudon,  J.  C.    Arboretum  et  Fruticetum  Britannicum  2,  892.    1838. 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


487 


M.  dioica  is  represented  in  the  Station  plantation  only  in  the 
800  series  under  the  number  819.  Ten  root-grafts  on  apple  seedlings 
were  made  January  18,  1908;  five  of  these  trees  were  planted  in  or- 
chard in  1910,  grew  vigorously  until  1916,  were  then  attacked  by  trunk 
blight  and  died  the  next  year.  In  a  general  way  growth  of  the  trees 
was  erect,  but  one  was  markedly  irregular  in  the  direction  of  branches ; 
lower  branches  were  long  and  straggling  and  the  upper  less  strictly 


FIG.  34. — SPREADING  TYPE  OF  M.  dioica,  JULY  11.     FIG.  35. — MORE 

UPRIGHT  FORM,  JULY  11 

Trees  of  this  species  are  of  slow  growth  and  dwarfish  habit,  as 
indicated  by  the  average  height  of  9  feet  at  ten  years  from  graft. 


erect  than  branches  of  the  other  trees.  Bark  of  trunk  rough,  dark 
brown,  on  young  branches  and  twigs  a  lighter  brown  with  a  tinge  of 
green.  Lenticels  numerous;  on  the  larger  branches  transversely  elong- 
ated, on  smaller  branches  nearly  round.  There  are  numerous  spurs  % 
to  1  inch  in  length  which  project  at  right  angles  from  the  branches. 
Buds  large,  thickly  covered  with  white  tomentum  and  perfectly  free, 
pointing  obliquely  upward.  That  the  trees  are  of  slow  growth  and 
dwarfish  habit  is  indicated  by  the  average  height  of  9  feet  at  ten  years 
from  graft.  The  least  upright  and  most  spreading  of  these  trees  is 
shown  in  Fig.  34,  the  more  upright  form  in  Fig.  35.  Other  trees  have 
been  propagated  and  grown  in  orchard,  but  none  are  now  living;  all 
have  been-killed  by  blight,  to  which  disease  this  form  has  proved  to  be 


488 


BULLETIN  No.  275 


[June, 


especially  susceptible.  The  only  representatives  of  the  form  now  in 
the  collection  are  two  on  Doucin  stocks  grown  in  the  greenhouse. 
These  were  grafted  in  February,  1910;  they  are  now  fourteen  years 
old,  healthy,  but  of  very  -slow  growth. 

Leaves. — Two  to  4  inches  long  by  1  to  1%  inches  wide,  elliptical 
or  some  of  the  smaller  ovate,  or  occasionally  lanceolate,  acute,  crenate, 
slightly  pubescent  on  both  sides  when  young,  becoming  glabrous  above 


FIG.  36. — BUD  CLUSTER  OF  M .  dioica,  MARCH  16, 

WITH  FLOWERS  NEARLY  OPEN 
The  interval  between  the  first  open  flower 
and  the  last  of  the  cluster  is  usually  three  or 
four  days. 

and  nearly  so  below,  dark  green;  petioles  slender,  %  to  1  inch  long, 
pubescent,  broadly  and  deeply  channelled. 

Flowers. — Borne  in  clusters,  mostly  from  terminal  buds  of  short 
spurs.  Of  77  clusters  recorded,  42  had  6  flowers  each,  4  had  7  each,  1 
had  8,  and  1  had  only  4.  In  some  cases  the  bud  axis  elongates  some- 
what, separating  the  flowers  so  that  they  appear  racemose,  but  in 
others  the  cluster  is  compact,  appearing  umbellate;  pedicels  10  mm. 
long,  stout,  pubescent.  In  unopened  buds  the  calyx  lobes  are  conniv- 
ent,  giving  a  pointed  appearance  to  the  apex  of  the  bud.  When  fully 
open  the  calyx  lobes  are  horizontal  and  the  flower  expands  10  to  12 
mm.  from  tip  to  tip  of  the  lobes;  the  lobes  are  5  in  number,  narrowly 
triangular,  acuminate  with  attenuated  point,  densely  tomentose  on 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  489 

both  sides,  grayish-green  with  tips  tinged  pink,  rather  thick  and 
rigid.  In  place  of  normal  petals  are  5  small  bracts  closely  resembling 
the  calyx  lobes  except  that  they  are  smaller  and  obtusely  pointed; 
they  alternate  with  the  calyx  lobes  and  are  thickly  covered  with  white 
tomentum.  Stamens  wanting,  not  even  rudiments  can  be  detected. 
Styles  variable  in  number;  of  11  flowers  examined  there  was  1  each 
with  7,  8,  10,  12,  and  15;  2  with  11  each,  and  4  with  14  each;  they 
vary  in  length  from  7  to  10  mm.  and  in  most  flowers  are  more  or  less 
contorted ;  in  the  flower  having  15  styles,  10  appeared  normal  and  were 
bent  but  little,  the  other  5  were  more  slender  and  much  contorted.  The 
outer  styles  are  connate  at  base  in  groups  of  2  or  3  and  are  sparingly 
pubescent  for  about  one-fourth  the  length ;  the  inner  styles  are  distinct 
and  glabrous.  Stigmas  are  mostly  rounded  capitate,  sometimes  oval 
and  usually  slightly  two-lobed.  At  anthesis  most  stigmas  glisten  with 
exudation.  Flowers  of  individual  clusters  do  not  open  simultaneously, 
commonly  the  interval  between  the  first  open  flower  and  the  last  of  the 
cluster  is  three  or  four  days.  A  bud  cluster  with  2  flowers  nearly  open 
is  shown  in  Fig.  36. 

Fruit. — The  root-grafted  trees  in  orchard  produced  a  few  flower 
clusters  in  1915,  but  no  fruit  matured;  in  1916  the  amount  of  bloom 
was  considerably  increased,  but  altho  166  flowers  were  hand  pollinated 
no  fruit  persisted  to  maturity.  Two  trees  in  pots  from  scions  top- 
worked  on  Doucin  stocks  February  12,  1910,  produced  3  fruits  in  1914, 
3  in  1915,  and  11  in  1916,  following  hand  pollinations  with  pollen  of 
various  orchard  varieties.  These  17  fruits  ranged  in  weight  from  18 
grams  to  66  grams  with  an  average  of  45  grams;  in  longitudinal  diam- 
eter from  34  to  61  mm.,  with  an  average  of  48  mm.;  and  in  transverse 
diameter  from  35  to  55  mm.  with  an  average  of  47  mm.  There  was 
marked  irregularity  in  numbers  of  carpels.  Ten  of  the  fruits  had  only 
the  normal  single  whorl  with  numbers  as  follows:  1  had  only  1,  5  had 
3  each,  3  had  4  each,  and  1  had  5.  Each  of  the  7  remaining  fruits  had 
a  more  or  less  complete  second  whorl  of  carpels  superposed  upon  the 
normal  whorl;  in  these  fruits  the  distribution  of  carpels  was  as  below; 

1  had  10  carpels,  5  in  each  whorl;  1  had  3  in  the  lower  whorl,  and 

2  in  the  upper;  2  had  4  in  the  lower  and  3  in  the  upper  whorl; 
2  had  3  in  the  lower  and   1   in  the  upper  whorl;   1  had  5  in  the 
lower  and  3  in  the  upper  whorl.  The  aggregate  of  good  seeds  from  the 
17  fruits  was  67;  of  these  55  were  produced  in  carpels  of  normal 
whorls  and  12  were  from  superposed  cells.   In  the  fruit  with  5  carpels 
in  each  whorl,  each  carpel  of  the  lower  whorl  bore  1  seed  and  3  of  the 
5  in  the  upper  whorl  each  bore  1  seed.    Maximum  seed  production  was 
reached  by  a  fruit  having  5  carpels,  4  of  which  bore  2  seeds  each  and 
the  remaining  carpel  1.  The  3  fruits  of  1915  were  parthenocarpic :  each 
had  a  single  whorl  of  3  carpels  and  each  carpel  contained  2  ovules,  but 
no  seeds  developed. 


490 


BULLETIN  No.  275 


[June, 


The  accompanying  fruit  description  is  from  fruits  of  cross  No. 
9703.  The  flowers  were  pollinated  with  Oldenburg  pollen  February  26 
and  the  mature  fruits  were  picked  and  described  June  2,  1916.  Two  of 
the  4  fruits  were  photographed  and  are  shown  in  Fig.  37.  The  fruit  on 


FIG.  37. — FRUITS  OF  CROSS  NUMBER  9703,  M.  dioica  x  OLDENBURG 
The  flowers  were  pollinated  February  26;  the  fruit  picked  June  2.   This 
fruit  is  oblong  in  shape  and  dull  yellow  in  color,  with  a  few  small,  greenish 
dots. 


the  left  weighed  57  grams,  calipered  51  mm.  in  vertical  diameter  and 
50  mm.  in  transverse  diameter;  its  companion  weighed  47  grams  and 
the  diameters  were  49  and  45  mm. 

Form  oblong,  irregular  at  both  base  and  apex,  transverse  section 
irregular,  ribbed,  sides  unequal,  dull  yellow  in  color,  skin  smooth,  ten- 
der, thin,  somewhat  unctuous,  scantily  covered  with  a  waxy  white 
bloom;  dots  few,  small,  regular,  round,  greenish,  inconspicuous.  Cavity 
shallow,  moderately  wide,  acute,  irregular;  stem  medium  in  length, 
slender,  green,  pubescent.  Calyx  of  medium  size,  pubescent,  open. 
Basin  medium  in  depth,  rather  broad,  irregular,  deeply  ridged.  Calyx 
lobes  small,  short,  broad,  acuminate,  reflexed  and  somewhat  separated 
at  base.  Calyx  tube  of  medium  size,  short,  cylindrical  in  form.  Core 
of  medium  size,  elliptical,  median,  half  open.  Carpels  obcordate,  emar- 
ginate,  tufted,  moderately  concave.  Seeds  plump,  rather  small,  dark 
brown.  Flesh  white  or  with  a  slight  yellowish  tinge,  tender,  rather 
dry,  mildly  subacid,  quality  only  fair.  The  fruit  at  left  of  figure  had 
4  carpels  in  the  normal  whorl  which  bore  4  seeds  and  3  carpels  in  a 
superposed  whorl  each  of  which  bore  1  seed.  The  fruit  at  the  right 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  491 

had  5  carpels  in  the  lower  whorl  which  bore  3  seeds  and  3  carpels  in 
the  upper  whorl  which  bore  2  seeds. 

Fruits  that  do  not  have  the  superposed  whorl  of  carpels  are  of 
roundish  form  and  much  less  irregular  at  base  and  apex,  otherwise 


FIG.  38. — FRUITS  OF  CROSS  NUMBER  9810,  dioica  x  OLDENBURG, 
NATURAL  SIZE,  PHOTOGRAPHED  JUNE  7,  1916 


they  are  the  same.  A  further  illustration  of  this  species  is  given  in 
Fig.  38.  This  is  cross  No.  9810.  There  were  5  buds  in  the  cluster,  4  of 
which  were  pollinated  with  Oldenburg  pollen  March  1,  1916.  Three 
fruits  matured,  were  photographed  June  7,  1916,  and  picked  for  de- 
scription June  16. 

Trees  of  this  species  have  the  general  appearance  of  upright  grow- 
ing varieties  of  the  common  apple  with  leaves  rather  smaller  than  is 
usual.  In  1916,  Grimes  pollen  wras  used  on  166  flowers  of  M.  dioica  on 
trees  in  orchard;  no  fruits  matured.  In  the  years  1913  to  1921,  156 
flowers'  on  trees  in  greenhouse  have  been  pollinated  by  pollen  from 
nine  orchard  varieties  and  three  crab  forms.  The  crosses  by  Yellow 
Transparent,  Stayman  Winesap,  and  one  of  two  crosses  by  Oldenburg 
failed.  The  ten  remaining  crosses  were  successful  in  varying  degrees 
and  67  fruits  matured,  252  seeds  were  planted,  and  137  seedlings 


492  BULLETIN  No.  275  [June. 

grew.  There  are  now  in  orchard  seventy-five  trees  representing  seven 
of  these  crosses  in  numbers  from  two  to  twenty-two,  and  ranging  in 
age  from  three  to  eight  years.  Unless  attacked  by  blight  most  of  these 
trees  should  reach  fruit  production. 

16.  Mains  floribunda  Siebold  (821) 

This  species  appears  to  have  been  first  mentioned  by  Louis  Van- 
houtte.1  In  his  work,  "Flore  des  Serres,"  three  colored  plates  illustrate 
the  plant  in  bud  and  flower  and  we  are  told  that  it  was  introduced 
from  Japan  by  Dr.  von  Siebold  under  the  name  of  Mains  floribunda. 
The  plant  grew  in  the  Vanhoutte  nurseries  several  years  without 
attracting  attention,  but  in  the  spring,  presumably  of  the  year 
1864,  it  flowered  so  abundantly  as  to  demonstrate  its  value  as  an  orna- 
mental. It  was  described,  illustrated,  and  since  then  has  received  many 
favorable  notices  in  various  journals.  It  was  brought  from  Japan  as  a 
cultivated  plant  and  it  is  doubtful  if  it  is  known  in  the  wild  state.  It 
has  been  largely  propagated  by  seeds  and  hence  numerous  forms  have 
appeared;  it  has  also  hybridized  with  other  species  and  some  of  the 
hybrid  seedlings  have  been  named  and  disseminated  by  nurseries. 

This  species  is  represented  in  the  collection  as  No.  821,  and  the 
trees  were  grown  from  scions  received  from  the  Arnold  Arboretum  in 
1908.  At  the  Arboretum  the  species  has  been  grown  for  many  years 
and  is  represented  by  both  yellow-  and  red-fruited  forms.  Scions  re- 
ceived here  were  from  the  typical  yellow- fruited  form  and  our  trees 
appear  identical  with  those  at  the  Arboretum.  The  general  form  is 
low  and  wide-spreading  with  a  strong  tendency  to  the  production  of 
long  wand-like  branches,  which  in  growing  take  a  more  or  less  up- 
right position,  but  later  become  nearly  horizontal.  In  the  autumn  of 
1923  one  of  the  two  root-grafts  made  in  1908  measured  17  feet  high,  21 
feet  in  spread,  and  9.0  inches  in  trunk  diameter  at  the  ground  surface. 
Bark  of  trunk  and  larger  branches  very  dark  brownish-black;  of  twigs 
bright  reddish-brown.  Lenticels  few,  small,  inconspicuous.  These  trees 
began  flowering  in  1912  and  bloomed  the  last  week  in  April  each  year 
until  1920,  when  the  first  flower  opened  May  7.  In  the  spring  of  1921, 
the  first  bloom  came  April  7;  in  1922,  April  17;  in  1923,  May  4.  May  2 
was  the  date  for  first  bloom  in  1924.  A  tree  top-worked  on  Grimes  in 
March,  1912,  has  formed  a  low,  round,  spreading  top  in  all  respects- 
similar  to  the  root-grafted  trees;  this  flowered  in  1915,  again  in  1916, 
and  abundantly  in  1917.  The  species  has  proved  satisfactory  on  Dou- 
cin  stocks  in  pots;  scions  inserted  February  12,  1912,  flowered  under 
glass  March  1,  1914,  February  22,  1915,  and  February  26,  1916,  and 
each  season  bore  fruit.  One  of  the  root-grafted  trees  as  it  appeared 
when  photographed  September  24,  1915,  is  shown  in  Fig.  39. 


'Vanhoutte,  Louis.    Flore  des  Serres  15.    1862-1865. 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


493 


Leaves. — Young  leaves  from  mixed  buds  are  various  in  form,  the 
majority  lanceolate,  some  elliptical  or  ovate  or  even  obovate,  but  gen- 
erally tending  toward  long  narrow  forms.  Petioles  short,  pubescent, 
margins  serrate  or  crenate,  acuminate,  lower  surfaces  finely  tomentose, 
above  nearly  glabrous.  Mature  leaves  of  non-flowering  shoots  2  to  3% 
inches  long,  ovate  or  oblong,  acute,  sharply  but  somewhat  irregularly 
serrate,  glabrous  thruout;  petioles  l/2  inch  long,  stout,  narrowly  and 


FIG.  39. — ROOT-GRAFTED  TREE  OF  M.  floribunda,  AS  PHO- 
TOGRAPHED SEPTEMBER  24,  1915 


deeply  channelled.  Leaf  texture  somewhat  stiff,  dark  green.  Detailed 
examination  of  100  leaves,  50  from  young  wood  and  50  from  older 
branches,  gave  an  average  length  of  3%  inches  and  width  a  little  more 
than  1  inch;  petioles  averaged  1  inch  in  length;  58  percent  of  the 
leaves  were  acute,  40  percent  acuminate,  and  2  percent  obtuse;  mar- 
gins were  crenate-serrate  in  three- fourths  of  the  leaves  and  serrate  in 
the  balance.  None  of  the  leaves  were  lobed. 

Flowers. — Produced  from  mixed  buds,  terminal  and  lateral  along 
terminal  shoots.  These  shoots  are  commonly  2  or  3  feet  in  length  or 
longer;  on  the  two-  and  three-year  old  wood,  at  intervals  of  about  % 


494 


BULLETIN  No.  275 


[June, 


inch  are  very  short  spurs,  each  of  which  produces,  from  the  terminal 
bud,  from  5  to  8  small  leaves  and  flowers,  in  numbers  as  determined 
from  count  of  541  clusters,  ranging  from  3  to  11  with  the  average  a 
little  above  6.  There  are  also  numerous  spurs,  3  to  6  inches  in  length, 


FIG.  40. — SHOOT  OF  M.  floribunda  IN  FLOWER,  APRIL  29.  FIG.  41. — 

BRANCH  IN  FRUIT  PHOTOGRAPHED  SEPTEMBER  16 
This  species  is  chiefly  valued  for  its  beauty  in  flower.  It  prop- 
agates readily  either  on  standard  or  dwarf  stocks  and,  with  little 
trouble,  can  be  used  freely  for  ornamental  planting. 


from  interior  and  larger  branches,  the  terminal  buds  of  which  produce 
leaves  and  flowers  as  do  the  buds  on  terminal  shoots.  The  attractive- 
ness of  the  tree  at  blooming  time,  however,  centers  in  the  long  shoots 
because  of  the  massing  of  color.  Within  a  length  of  14  inches  on  one 
shoot  were  26  flower  clusters  opening  160  flowers,  literally  a  mass  of 
bloom.  Young  buds  are  of  an  attractive  deep  red,  but  fade  to  pink 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  495 

before  anthesis;  just  before  opening  they  attain  a  length  of  7  mm.  and 
a  breadth  of  5  mm.  Fully  open  flowers  expand  about  1  inch  and  are 
then  light  pink  or  in  some  cases  nearly  white.  Pedicels  are  about  an 
inch  in  length,  slender,  green,  pubescent.  Calyx  lobes  5,  lanceolate, 
erect  in  bud,  acute,  slightly  pubescent  outside,  and  densely  pubescent 
within  and  on  the  margins.  Petals  oblong  or  elliptical,  9  mm.  long  by  4 
mm.  wide,  claw  very  short.  The  range  in  number  of  stamens  is  from 
18  to  30,  the  average  is  about  21,  filaments  slender,  about  5  mm.  long, 
anthers  plump,  light  yellow.  Styles  3  to  5;  of  44  flowers  examined  5 
had  3  each,  23  had  4  each,  and  16  had  5  each;  they  vary  in  length  from 
5  to  8  mm.,  connate  one-third  the  length  and  hairy  from  base  to  point 
of  separation.  A  portion  of  a  flowering  branch  photographed  April  29, 
1915,  is  shown  in  Fig.  40. 

Fruit. — Very  small,  round,  or  slightly  oblate,  somewhat  conical, 
and  flattened  at  the  apex.  Averaged  from  100  fruits  the  weight  is 
found  to  be  .87  gram,  longitudinal  diameter  11  mm.,  and  transverse 
diameter  12  mm.  Color  light  orange-yellow  with  brownish  blush  on 
side  exposed  to  sun;  bloom  scanty  or  none,  skin  thin,  rather  tough, 
smooth,  polished;  cavity  shallow,  broad,  regular;  stem  rather  long,  20 
to  25  mm.,  slender,  erect,  usually  red,  glabrous;  basin  shallow,  medium 
in  width,  obtuse,  irregular.  Calyx  lobes  uniformly  deciduous;  the 
russet  scar  left  by  the  lobes  small  and  slightly  depressed  below  the 
surface;  core  large  in  proportion  to  the  size  of  the  fruit,  round,  closed. 
Carpels  roundish,  emarginate,  glabrous,  moderately  concave.  Flesh 
yellowish,  firm,  rather  dry,  acid.  Ranges  low  in  seed  production;  of 
100  fruits  3  had  5  seeds  each,  29  had  4  each,  26  had  3  each,  28  had  2 
each,  and  14  had  1  each.  The  average  is  2.79  or  approximately 
one  for  every  3%  ovules  present.  A  branch  in  fruit  photographed 
September  16,  1915,  is  shown  in  Fig.  41. 

M.  ftoribunda  is  certainly  attractive  when  in  flower;  less  can 
be  said  of  its  beauty  in  the  fall  because  of  the  dull  color  of  the  fruit. 
It  is  chiefly  valued  for  its  spring  beauty  and  as  it  propagates  readily 
either  on  standard  or  dwarf  stocks  it  can  be,  with  little  trouble,  added 
to  any  collection  or  used  freely  for  ornamental  planting. 

17.  Mains  fusca  (841) 

Schneider,  C.  K.    Illus.  Handb.  Laubholzh.  1,  723.    1906. 

Pyrus  rivularis  Douglas  ex.  Hooker  Fl.  Bor.  Amer.    1,  203.    1839. 

Mains  rivularis  Roemer  Syn.  Mon.  3,  215.    1847. 

The  Oregon  crab-apple  of  the  Pacific  coast  ranges  from  northern 
California  to  Alaska.  Scions  received  from  the  U.  S.  Department  of 
Agriculture  under  the  number  19668,  January,  1907.  Attempts  to 
propagate  by  both  root-  and  top-grafting  failed.  A  second  lot  of  scions 
received  from  the  Arnold  Arboretum  January,  1908,  was  propagated 
by  both  root-  and  top-grafting  as  number  841.  The  species  is  now 


496 


BULLETIN  No.  275 


[June, 


represented  in  the  collection  by  one  tree  root-grafted  January  20,  1908, 
and  one  top-worked  on  Virginia  Crab  on  April  7,  1908.  Also  by  two 
trees  root-grafted  in  1914.  The  root-grafted  trees  are  healthy,  but  de- 
cidedly dwarf,  advancing  year  by  year  by  very  small  increments.  The 
graft  of  1908  now  sixteen  years  old  stands  8  feet  in  height,  has  a  spread 


FIG.  42. — ROOT-GRAFTED  TREE  OF  M.  fusca,  AS  IT  APPEARED  WHEN  NINE  YEARS  OLD. 
FIG.  43. — TOP- WORKED  TREE  OF  M.  fusca  ON  VIRGINIA  CRAB,  AT  THE  SAME  AGE 

The  root-grafted  trees  of  this  species  are  healthy,  but  decidedly  dwarf, 
making  very  small  gains  each  year.  Flowering  is  very  irregular,  and  later  than 
on  any  other  form  of  Malus  in  the  collection. 


of  5  feet,  and  a  trunk  diameter  of  2%  inches.  It  produced  a  few  bud 
clusters  in  1914,  but  they  fell  without  opening  flowers  and  the  tree  has 
not  flowered  since.  Appearance  of  the  tree  when  nine  years  old  is 
shown  in  Fig.  42. 

The  tree  on  Virginia  Crab  has  produced  numerous  small  branches 
which  have  made  a  very  thick  rounded  top ;  as  measured  in  the  fall  of 
1923  it  was  14  feet  high,  had  a  spread  of  10  feet,  and  a  trunk  diameter 
of  5  inches.  This  tree  as  photographed  in  October,  1916,  when  nine 
years  old,  is  shown  in  Fig.  43.  A  few  flowers  were  produced  in  1915 
and  greater  numbers  in  the  two  following  years ;  then  for  four  years  it 
did  not  flower;  in  each  of  the  years  1921  and  1922  it  flowered  spar- 
ingly, but  not  at  all  in  the  last  two  seasons.  Flowering  appears  to  be 
very  irregular  and  when  flowers  are  produced  they  open  later  than 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  497 

those  of  any  other  form  of  Malus  in  the  collection.  Bark  of  trunk  and 
branches  dark  grayish-brown;  of  twigs  reddish-brown,  pubescent.  The 
habit  of  growth  is  ascending. 

Leaves. — Rather  small  and  of  various  forms;  on  flowering  shoots 
they  are  ovate,  obovate,  oblong,  orbicular  or  even  narrowly  lanceolate, 
mostly  sharply  serrate,  acute  or  acuminate,  or  sometimes  variously 
incised  and  occasionally  three-lobed,  pubescent  below,  sparsely  villous 
above.  Leaves  produced  later  on  new  non-flowering  shoots  vary  in 
outline  from  ovate  to  lanceolate,  but  the  greater  portion  approximate 
the  ovate  form,  ll/2  to  3%  inches  long,  %  to  1%  inches  broad.  Some 
leaves  are  obtusely  rounded  to  the  petiole,  others  have  a  slight  taper; 
mostly  three-lobed,  the  small  lateral  lobes  above  the  middle;  often  the 
large  central  lobe  is  incised  in  such  manner  as  to  appear  three-lobed. 
Margins  serrate  or  sometimes  crenate-dentate  below  and  serrate  to- 
wards the  apex,  acuminate,  becoming  glabrous  above  and  nearly  so 
below.  Petioles  l/2  to  1  inch  long,  slender,  pubescent  when  young,  be- 
coming glabrous.  Stipules  small,  linear,  in  part  persistent.  In  spring 
and  early  summer  the  leaves  are  thin  and  delicate  in  texture,  later 
they  become  somewhat  coriaceous. 

Flowers. — Borne  from  terminal  buds  and  to  some  extent  from 
upper  lateral  buds  of  terminal  shoots  and  from  terminal  buds  of  nu- 
merous short  spurs.  The  number  of  buds  to  the  cluster  ranges  much 
higher  than  for  other  species;  30  clusters  examined  have  distribution 
as  follows:  2  had  7  buds  each,  5  had  10  buds  each,  5  had  11  each,  13 
had  12  each,  3  had  13  each,  and  2  had  14  buds  each.  Buds  small,  glo- 
bular, greenish-white  or  sometimes  faintly  tinged  with  pink,  the  axis 
is  short  and  the  buds  appear  umbellate.  Pedicels  slender,  18  to  22  mm. 
long,  each  with  from  1  to  3  linear,  brown  bracts,  usually  on  the  basal 
half,  slightly  pubescent,  as  is  also  the  ovary.  Calyx  lobes  obtusely  tri- 
angular, acute,  pubescent  outside,  more  densely  so  inside,  deciduous. 
Flower  expands  13  mm.,  petals  white,  5  to  7  mm.  long,  3  to  5  mm.  wide, 
oval  or  nearly  rotund,  rounded  at  apex,  claw  very  short;  stamens  16 
to  20,  filaments  slender,  3  to  5  mm.  long,  anthers  large,  plump,  creamy 
white;  pollen  grains  large,  elliptical,  almost  white;  styles  3  or  4,  slen- 
der, 4  mm.  long,  connate  half  the  length,  glabrous,  tips  compressed, 
stigmas  oval,  elliptical.  The  flowers  are  fragrant  and  suggest  Phila- 
delphus. 

Fruit. — Oblong,  regular  at  base  and  apex,  small;  34  fruits  aver- 
aged give  the  individual  weight  as  .46  gram,  vertical  diameter  9.7 
mm.,  transverse  diameter  9  mm.  Color  depends  upon  degree  of  matur- 
ity. Until  the  first  of  October  all  are  green.  Fruits  gathered  October 
25  were  nearly  all  yellow,  some  having  a  light  red  blush  and  a  few 
were  partially  colored  a  darker  brownish-red,  none  were  "dark  purple, 
almost  black"  as  described  by  Nuttall.  Skin  smooth,  thin,  tough;  no 
dots  apparent;  cavity  shallow,  broad,  obtuse,  regular;  stem  slender,  20 


498 


BULLETIN  No.  275 


[June, 


to  22  mm.  long,  erect,  green,  glabrous;  basin  shallow,  broad,  obtuse, 
irregular,  ribbed;  core  small,  oblate,  distant,  closed;  carpels  elliptical, 
entire,  mucronate,  glabrous,  varying  in  number  from  3  to  5 ;  of  the  34 
fruits  dissected,  23  had  3  carpels  each,  10  had  4  each,  and  1  had  5. 
Seeds  plump,  of  medium  size,  light  brown;  the  average  of  seeds  to  each 


FIG.  44. — SOME  SMALL-FRUITED  CBABS,  NATURAL  SIZE 

Left  to  right:    M.  arnoldiana  (802),  M.  fusca  (841),  M.  floribunda  (821), 
M.  sargenti  (843),  M.  atrosanguinea  (804),  M.  toringo  (19664),  dwarf  form. 


fruit  as  found  for  34  fruits  is  1.3;  this  is  the  lowest  average  of  any  of 
the  crab  group  examined.  Flesh  white,  moderately  juicy,  acid.  A 
single  fruit  photographed  natural  size  may  be  seen  the  second  from  the 
left  in  Fig.  44. 

18.  Malus  dawsoniana  Rehder.    Sargent,  C.  S.    Trees  and  Shrubs 

2,23.    1913. 

Scions  of  this  crab  were  received  from  the  Arnold  Arboretum  as 
Malus  rivularis  var.  in  1908,  and  again  in  1912,  both  root-grafts,  and 
top-grafts  were  made,  and  it  is  now  represented  in  the  collection  by 
three  trees  top-worked  on  Doucin  stocks,  grown  in  pots  in  the  green- 
house; one  grafted  in  1910,  the  others  in  1914.  In  the  orchards  are 
four  trees,  one  top-worked  on  Grimes  in  1912  and  three  from  root- 
grafts  made  the  same  year.  The  trees  in  orchard  are  of  remarkably 
vigorous  growth,  forming  very  dense,  symmetrical  crowns.  Branches 
are  ascending  becoming  somewhat  spreading.  Production  of  a  very 
great  number  of  short  interior  branches  seems  characteristic  of  the 
species;  these  branches  account  for  the  observed  density  and  it  is  from 
their  terminal  buds  that  most  of  the  flowers  are  borne.  Bark  of  trunk 
and  larger  branches  very  dark,  rough,  and  scaly.  Shoots  of  the  current 
year  are,  at  first,  dull  green,  but  become  light  brown  before  the  close  of 
the  season. 


19261  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  499 

Leaves. — Those  of  terminal  shoots  elliptical,  oval,  or  ovate,  2  to  5 
inches  long,  %  to  2%  inches  wide,  acute,  irregularly  crenate  or  cren- 
ate-serrate,  glabrous  above,  scantily  pubescent  below.  Petioles  %  to 
1^4  inches  long,  pubescent.  Leaves  from  spurs  and  short  interior 
branches  small  and  of  various  forms.  Flowers  from  terminal  buds  of 
short,  mostly  interior,  branches,  usually  5  or  6  in  each  cluster;  buds 
deep  pink  fading  to  white  as  petals  open,  apex  rounded. 

Flowers. — Expand  35  mm.,  calyx  lobes  narrowly  triangular  5  mm. 
long,  acuminate,  pubescent,  becoming  reflexed ;  petals  oval  or  obovate, 
apex  round,  18  mm.  long,  10  mm.  wide,  pure  white,  claw  short,  slender; 
stamens  20,  filaments  slender,  9  mm.  long,  anthers  plump  of  medium 
size,  light  yellow,  styles  5,  slender,  8  mm.  long,  connate  for  3  mm.  from 
base,  glabrous  at  base,  a  few  hairs  about  the  point  of  separation, 
stigmas  small,  oval,  capitate,  ovary  pubescent,  tinged  red;  pedicels 
stout,  12  to  15  mm.  long,  pubescent. 

Fruit. — Oblong  or  obovate-oblong.  For  20  fruits  weights  range 
from  12  to  18  grams  with  an  average  of  16  grams,  average  vertical 
diameter  is  32  mm.,  average  transverse  diameter  24  mm.  Green  or 
yellowish-green,  sometimes  with  a  light  red  blush,  bloom  rather  heavy, 
waxy,  white;  skin  smooth,  tough,  thin;  dots  few,  regular  or  irregular, 
russet,  conspicuous;  cavity  shallow,  narrow,  obtuse,  regular;  stem  slen- 
der, erect,  glabrous,  11  to  21  mm.  in  length.  Calyx  small,  open  or 
closed,  pubescent;  basin  shallow,  broad,  or  often  with  no  depression; 
calyx  lobes  long,  slender,  accuminate,  erect  or  reflexed,  mostly  persist- 
ent; an  occasional  fruit  is  found  with  calyx  lobes  regularly  deciduous; 
calyx  tube  long,  funnel-form;  core  small,  elliptical,  median,  closed; 
carpels  obovate,  emarginate,  tufted,  slightly  concave;  seeds  plump, 
medium  size,  light  brown;  flesh  yellowish,  firm,  crisp,  juicy,  sharply 
subacid.  Only  one  attempt  to  breed  this  crab  has  been  made.  In  1918 
using  Jonathan  as  the  pollen  parent  69  flowers  were  pollinated,  but  no 
fruits  developed. 

19.  Mains  halliana  (823)  Koehne.  Gatt.  Pomac.,  27.    1890. 

This  is  another  of  the  species  of  Malus  from  Japanese  gardens 
introduced  by  Dr.  von  Siebold.  It  does  not  seem  to  be  known  in  the 
wild  state ;  some  have  thought  that  it  came  originally  from  China  and 
have  associated  it  with  the  Chinese  Malus  spectabilis.  The  affinities  of 
the  species,  however,  appear  to  be  with  either  Malus  baccata  or  Malus 
toringo  rather  than  with  spectabilis,  and  there  is  no  definite  record  of 
the  plant  back  of  its  existence  in  Japanese  gardens.  It  has  appeared 
under  various  trade  names  as  Pyrus  malus  floribunda,  Pyrus  baccata 
parkmani,  and  Pyrus  toringo  parkmani.  The  most  complete  descrip- 
tion is  given  by  Dr.  Alfred  Rehder  in  Sargent's  "Trees  and  Shrubs."1 


'Sargent,  C.  S.     Trees  and  Shrubs  1,  35.    1905. 


500  BULLETIN  No.  275  [June, 

This  species  is  represented  in  the  Station  collection  as  No.  823,  by 
two  trees  grown  from  root-grafts  on  apple  seedling  stocks,  made  in 
January,  1908.  These  trees  have  supplied  scions  for  further  propaga- 
tion. Three  trees  grafted  in  February,  1912,  are  now  in  orchard  on  the 
Douglas  tract  and  12  trees  grafted  in  January,  1914,  were  planted  in 
the  south  orchard  in  the  spring  of  1915.  The  trees  first  propagated 
and  now  sixteen  years  from  the  grafts  are  still  small  and  shrubby;  the 
two  trees  average  7  feet  9  inches  in  height,  9  feet  3  inches  in  spread, 
and  the  average  trunk  diameter  is  2.7  inches.  Bark  of  trunk  dark 
grayish-brown,  branches  are  of  the  same  color  but  lighter  in  shade; 
twigs  reddish-brown,  more  or  less  whitened  with  scarf  skin  and  scant- 
ily pubescent. 

Leaves. — Mostly  ovate  varying  to  elliptical  or  some  of  the  smaller 
lanceolate,  1%  to  3%  inches  long,  %  to  1%  inches  wide,  acute  or  acu- 
minate, obtusely  serrate  to  nearly  entire,  glabrous  both  sides,  except 
that  when  young  there  are  some  long  hairs  along  the  glandular  mid- 
rib above;  these  soon  disappear;  upper  surface  dark  shining  green, 
below  lighter.  Petiole  short,  %  to  %  inch  in  length,  at  first  pubescent, 
but  soon  becoming  glabrous;  deep  red  or  purple,  the  color  extending  up 
the  prominent  midrib  and  gradually  diminishing  towards  the  apex. 
Texture  thick,  leathery.  The  small  ovate  or  lanceolate  serrate  stipules 
mostly  persistent.  Late  in  the  fall  many  leaves  become  more  or  less 
purple. 

Flowers. — Flowering  began  in  1915  with  the  production  of  a  few 
clusters.  In  1916  the  number  was  considerably  increased;  all  thus  far 
borne  are  from  terminal  buds  of  shoots  or  spurs.  Of  30  clusters  exam- 
ined one  had  3  flowers,  5  had  5  flowers  each,  17  had  6  each,  and  7  had 
7  each.  Flowers  expand  1  inch.  Pedicels  slender,  30  to  32  mm.  long, 
glabrous,  dark  purplish.  Ovary  glabrous,  dark  red;  calyx  lobes  5, 
oblong,  truncate,  about  2  mm.  long,  glabrous  outside,  pubescent  with 
white  wool  on  margin  and  inside,  dark  purplish-red.  Petals  varying  in 
number  from  10  to  13,  ovate  or  sometimes  obovate  about  13  mm.  long 
by  9  mm.  wide  tapering  rather  abruptly  to  the  slender  claw  which  is  1 
to  2  mm.  long.  Buds  deep  reddish-pink;  as  the  petals  expand  they 
show  various  shades  of  pink,  but  when  fully  open  are  of  uniform  light 
rose-pink.  Stamens  25  to  35,  filaments  slender,  5  to  10  mm.  long; 
anthers  plump,  light  yellow.  In  most  clusters  the  central  flower  is 
staminate,  occasionally  2  staminate  flowers  are  found  in  a  cluster  and 
on  the  other  hand  all  flowers  of  some  clusters  are  hermaphrodite. 
Most  flowers  have  from  2  to  4  petaloid  stamens.  Styles  2  to  5,  mostly 
5,  about  12  mm.  long,  purple,  connate  for  a  length  of  2  mm.  or  about 
one-sixth  the  total  length,  hairy  with  thick  matted  wool  from  base  to 
above  the  point  of  separation  or  about  half  the  length  of  the  styles; 
stigmas  yellow,  small,  oval,  oblique.  Altho  flowers  were  numerous  on 
both  trees  in  the  spring  of  1916  neither  tree  matured  any  fruit.  On  one 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  501 

tree  106  flowers  in  30  clusters  were  emasculated  and,  on  May  5,  hand 
pollinated  by  Oldenburg,  but  neither  these  nor  the  flowers  left  open  to 
insect  visitors  developed  fruit.  In  later  years  flowers  were  pollinated 
by  Yellow  Transparent,  Jonathan,  and  Domine,  but  in  no  case  did 
fruits  mature.  The  trees,  however,  have  borne  fruits,  presumably  from 
insect  pollination. 

Fruit. — The  average  of  fruits  weighed  is  0.45  gram;  vertical  diam- 
eter 8  mm.,  transverse  diameter  9  mm.;  oblate,  regular  at  base  and 
apex,  sides  equal;  ground  color  green,  over-color  purplish-red,  skin 
smooth,  tough,  thin,  dots  none,  no  cavity  and  no  depression  at  the 
truncate  apex,  calyx  lobes  deciduous,  stem  slender,  33  to  38  mm.  long, 
red,  glabrous;  core  large,  round,  median,  closed;  carpels  roundish,  en- 
tire, glabrous,  deeply  concave;  flesh  greenish,  firm,  juicy,  acid.  The 
delicate  appearance  of  the  foliage  at  flowering  time,  the  varying 
shades  of  pink  in  the  flower,  and  the  distinctness  with  which  each 
flower  cluster  stands  out  are  features  that  combine  to  enhance  the 
beauty  of  this  shrub. 

20.  Mains  ioensis  (825)  (Wood)  Britton  and  Brown.  Illus.  Fl.  2, 
235.  1897. 

Pyrus  coronaria  var.  ioensis  Wood  Class  Book,  333.    1860. 
Pyrus  ioensis  Bailey.  Amer.  Gard.    12,  473.    1891. 

The  native  wild  crab  of  Illinois  and  adjacent  states.  Scions  re- 
ceived from  the  Arnold  Arboretum  in  January,  1908,  and  propagated 
as  No.  825.  Ten  root-grafts  on  ordinary  apple  seedling  stocks  were 
made  January  17,  1908;  three  grew;  two  lived  to  be  planted  in  orchard 
April  30,  1910;  one  of  these  was  vigorous  from  the  beginning  and  still 
survives ;  the  other  was  weak  at  time  of  planting  and  died  the  second 
year  in  orchard.  The  one  living  tree,  now  sixteen  years  old,  is  sym- 
metrical, round-topped,  somewhat  spreading;  height  19  feet  2  inches, 
spread  19  feet  5  inches;  trunk  diameter  6.6  inches.  The  bark  of 
trunk  and  branches  is  dark  grayish-brown,  young  twigs  reddish- 
brown  thickly  covered  with  gray  pubescence.  Thorn-like  spurs  are 
numerous. 

Leaves. — Three  to  5  inches  long,  1  to  2%  inches  wide,  ovate, 
oblong,  or  elliptical  in  outline,  tapering  below  to  the  stout,  pubescent 
petiole  which  is  from  1  to  1%  inches  in  length;  variously  dentate, 
notched  or  lobed,  acute  or  often  obtuse;  pubescent  below,  and  when 
young,  with  scattered  hairs  above.  At  maturity  glabrous  above  and 
nearly  free  from  pubescence  below  except  along  the  midrib  and  veins. 

Stipules  small,  linear,  in  general  caducous,  but  occasionally  per- 
sisting and  falling  with  the  leaves.  After  frosts  the  leaves  become 
yellow,  or  dark  red,  or  purplish,  falling  earlier  than  do  those  of  orchard 
varieties  of  apples. 


502  BULLETIN  No.  275  [June, 

Flowers. — The  first  flowers  were  borne  in  1913,  five  years  from 
the  graft;  the  amount  of  bloom  has  increased  each  year  since.  Flower 
clusters  are  single,  terminating  short  twigs  and  spurs.  The  inflores- 
cence is  cymose  and  the  bases  of  the  pedicels  are  more  or  less  verti- 
cally separated,  suggesting  a  raceme.  The  number  of  flowers  in  a  clus- 
ter ranges  from  3  to  6.  Of  50  clusters  2  had  3  flowers  each,  18  had  4 
each,  27  had  5  each  and  3  had  6  each.  Buds  are  globular,  deep  pink; 
as  flowers  open  the  petals  fade  somewhat,  but  remain  pink.  Pedicels 
rather  stout,  31  to  37  mm.  long,  pubescent.  Ovary  pubescent;  calyx 
lobes  5,  triangular,  slender,  acuminate,  pubescent  both  sides.  Flowers 
expand  45  mm.  Petals  24  mm.  long  by  13  mm.  broad,  oval  or  ellip- 
tical, emarginate,  tapering  below  to  the  slender  claw  which  is  4  to  5 
mm.  long.  The  long  claw  so  separates  the  5  petals  that  the  flower  has 
a  very  open  appearance.  Stamens  20,  filaments  slender,  10  to  13  mm. 
long;  anthers  light  yellow,  becoming  reddish-brown  after  dehiscence. 
Styles  5,  slender,  13  mm.  long,  tinged  with  red,  connate  one-third  the 
length  and  hairy  from  base  to  above  the  point  of  separation;  stigmas 
capitate,  oval.  Because  of  the  elongation  of  the  bud  axis  the  clusters 
are  very  open;  there  is  no  crowding,  each  flower  is  distinct,  free  from 
its  neighbors. 

Fruit. — Round,  irregular  at  base,  and  somewhat  ribbed  at  apex, 
green,  scantily  covered  with  waxy,  gray  bloom;  weight  and  dimensions 
as  averaged  from  100  fruits  from  the  tree  described  are  as  follows; 
weight  13.04  grams,  longitudinal  diameter  27  mm.,  transverse  diameter 
30  mm.  A  further  lot  of  212  fruits  obtained  from  a  wild  roadside  tree, 
near  Olney,  Richland  county,  gave  the  following  averages:  weight  7.12 
grams,  longitudinal  diameter  22  mm.,  transverse  diameter  25  mm.  Av- 
erages for  the  aggregate  of  fruits  are,  weight  9  grams;  longitudinal  di- 
ameter 23  mm. ;  transverse  diameter  26  mm.  Fruit  from  the  wild  tree 
was  distinctly  smaller  than  that  from  the  tree  in  orchard.  This  may  be 
a  varietal  difference  or  with  equal  probability  a  difference  due  to  envir- 
onment, one  tree  being  under  culture,  the  other  in  an  undisturbed 
fence  row.  A  further  difference  in  the  two  lots  of  fruits  is  seen  in  seed 
production.  The  average  of  good  seeds  for  the  wild  fruits  is  3.86;  for 
the  tree  under  cultivation  4.89. 

Skin  smooth,  unctuous,  tough,  thin;  dots  many,  small,  round,  dark 
gray,  inconspicuous;  cavity  of  medium  depth,  rather  broad,  acute; 
stem  long,  about  34  mm.,  slender,  somewhat  clavate,  erect,  green, 
pubescent;  base  of  the  stem  often  thickened  and  corrugated;  basin  me- 
dium in  depth  to  deep,  rather  broad,  acute,  irregular,  ribbed.  Calyx 
lobes  small,  rather  long  and  slender,  acute,  fleshy  at  base,  prect,  in- 
flexed;  the  tips  finally  wither  away  leaving  the  apex  of  the  fruit 
crowned  with  the  browned,  dead  styles,  which  persist  from  the  apex 
with  the  protruding  "pistil  point."  This  "pistil  point"  is  enlarged  and 
of  pyramidal  form;  it  is  projected  thru  and  nearly  fills  the  calyx  tube, 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  503 

so  that  this  tube,  instead  of  contracting  to  a  point  at  its  base,  is  broad- 
est at  base  and  tapers  towards  the  apex.  This  construction  is  peculiar 
and  has  not  been  encountered  in  any  other  species  of  Malus.  The  core 
is  of  medium  size,  round,  median,  closed;  core  lines  clasping;  they  are 
hard,  bony,  forming  a  conspicuous  division  between  core  and  outer 
flesh.  The  normal  carpels  are  5  and  in  addition  there  are  5  rudiment- 
ary carpels  alternating  with  the  others,  not  appearing  as  cells,  but  as 


FIG.  45. — FRUITS  OF  THREE  OF  THE  CRAB  FORMS,  NATURAL  SIZE 
Left  to  right:  Yellow  Siberian  Crab   (857),  M.  sylvestris  jastigiata  bifera 
(820),  M.  ioensis  (825). 

more  or  less  straight  lines  of  hard  bony  tissue.  The  5  carpels  forming 
cells  are  roundish,  deeply  concave  when  seeds  have  developed,  and  only 
slightly  so  when  the  ovules  are  abortive.  Seeds  are  large,  plump,  and 
of  dark  red  color.  The  flesh  is  yellowish,  firm,  crisp,  juicy  outside,  the 
core  lines  dry  and  mealy  within,  very  acid.  A  single  fruit  may  be  seen 
at  the  right  in  Fig.  45.  M.  ioensis  has  been  used  as  the  female  parent  in 
six  crosses  with  six  orchard  varieties  as  pollen  parents  and  all  of  these 
crosses  were  reasonably  successful  in  fruit  production.  The  total  of 
pollinations  was  469  and  181  fruits  matured;  1,049  seeds  were  planted, 
an  average  of  5.79  seeds  from  each  fruit.  Approximately  45  percent  of 
the  seeds  germinated,  but  the  seedlings  were  so  deficient  in  vitality 
that  one-fourth  of  them  died  before  time  to  plant  in  nursery;  others 
died  each  year  until  in  the  fall  of  1923  only  20  of  469  seedlings  were 
living  and  65  percent  of  these  graded  as  "poor"  and  will  not  survive  an- 
other year.  The  five  best  trees  may  survive  to  fruiting,  but  this  is 
doubtful. 

The  experience  with  M.  ioensis  as  a  mother  plant  gives  no  en- 
couragement to  its  use  in  breeding. 


504  BULLETIN  No.  275  [June, 

21.  Mains  ioensis  ft.pl.  (826) 

Scions  received  January  9,  1908,  were,  in  part,  worked  as  root- 
grafts  on  ordinary  apple  seedlings  on  January  20  and,  in  part,  stored 
and  then  on  April  6  inserted  as  top-grafts  on  a  young  tree  of  Fameuse. 
Some  of  the  top-worked  scions  made  a  feeble  start,  but  all  died  before 
the  end  of  the  first  season.  Five  of  the  root-grafts  grew  thru  the 
season,  were  stored  in  a  pit  for  the  winter,  and  again  planted  in  nurs- 
ery in  the  spring  of  1909.  Four  trees  survived  in  the  spring  of  1910r 
and  were  planted  permanently  in  orchard.  Growth  during  the  early 
years  was  slow;  in  later  years  more  rapid.  The  trees  have  formed 
rounded,  spreading,  symmetrical  crowns  with  numerous  branches  push- 
ing obliquely  upward.  The  largest  tree  measured  in  the  fall  of  1923 
was  16  feet  4  inches  high,  had  a  spread  of  15%  feet  and  a  trunk 
diameter  of  5.5  inches.  The  trees  flowered  sparingly  for  the  first  time  in 
1913;  each  year  since  the  amount  of  bloom  has  increased  until  now  it 
is  abundant.  Flowers  are  borne  singly  or  in  clusters  of  3  to  5.  In 
clusters  the  axis  is  elongated  and  the  inflorescence  racemose.  Buds 
just  before  opening  are  bright  pink,  globular,  %  inch  or  more  in  diam- 
eter. Fully  open  flowers  expand  from  2%  to  2%  inches;  pedicels  are 
stout,  heavily  pubescent,  bracteate,  40  to  45  mm.  in  length.  Calyx 
lobes  5,  triangular,  acuminate,  8  mm.  long,  densely  pubescent  both 
sides,  tips  slightly,  reflexed  in  fully  open  flowers.  Petals  large,  32  mm. 
long  by  24  mm.  wide,  oval,  somewhat  abruptly  contracted  to  the  long 
claw,  margin  usually  more  or  less  waved,  varying  in  number  from  18 
to  28,  with  the  average  for  14  flowers  examined,  23;  stamens  range  in 
number  from  25  to  34  with  an  average  of  30,  filaments  slender,  the 
outer  19  mm.  long,  the  inner  successively  somewhat  shorter;  anthers 
large,  plump,  orange-yellow.  Petaloid  stamens  occur  in  most  flowers  in- 
all  degrees  of  modification.  Styles  18  mm.  long,  slender,  reddish  in 
color,  varying  in  number  from  9  to  11,  free  to  the  base,  pubescent  one- 
third  the  length.  Stigmas  irregularly  oval. 

When  not  in  flower  these  trees  are  indistinguishable  from  those 
of  M.  ioensis  (825).  No  fruits  have  been  produced.  Ten  flowers  on  a 
tree  on  dwarf  stock  in  the  green  house  were  hand-pollinated  in  the 
spring  of  1915  with  Yellow  Transparent  pollen,  but  no  fruit  develop- 
ment followed.  Pollen  of  this  form  of  Malus  was  used  on  4  flowers  of 
Yellow  Transparent,  but  without  result.  Evidently  the  floral  modifica- 
tions are  such  as  to  preclude  the  use  of  this  plant  in  breeding.  This  full 
flowered  form  of  M.  ioensis  was  introduced  25  or  more  years  ago 
by  E.  A.  Bechtel's  Sons  of  the  Staunton  Nursery  at  Staunton,  Macou- 
pin  county,  as  Bechtel's  Double-Flowered  American  Crab.  It  is  said 
to  have  originated  near  Staunton.  The  plant  deserves  a  place  in  any 
collection  of  ornamentals  for  the  beauty  of  its  flowers  and  particularly 
of  the  large,  bright  pink  buds. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  505 

22.  Malus,  Fluke  Apple,  Mercer  County  Crab,  Fluke 
Wild  Crab  (822) 

Scions  received  from  the  Arnold  Arboretum  in  January,  1908. 
Several  root-grafts  made  January  11  were  planted  in  nursery  May  7; 
most  of  these  started  growth  but  all  died  before  the  end  of  the  first 
season.  April  6,  1908,  several  scions,  reserved  for  the  purpose,  were 
top-worked  on  a  Sops  of  Wine  tree  that  was  then  four  years  old ;  these 
scions  grew,  forming  a  round,  somewhat  spreading  top.  This  tree  was 
removed  to  another  orchard  in  February,  1913;  it  bloomed  in  1914, 
but  died  in  the  fall  of  that  year  from  blight  which  attacked  the  trunk. 
In  1910  scions  from  the  top- worked  tree  were  grafted  on  a  potted 
paradise  stock.  This  tree  is  still  living  and,  tho  small,  it  flowered  in 
each  of  the  years  1913,  1914,  1916,  and  1917;  in  each  of  the  two  earlier 
years  hybrid  fruits  were  matured,  in  1916  the  pollinations  all  failed, 
and  in  1917  only  1  fruit  matured.  Again  in  1912  scions  from  the  top- 
grafted  tree  were  used  in  root-grafting  and  seven  of  the  trees  grown 
are  now  in  orchard  on  the  Douglas  tract  as  trees  15  to  21  in  Row  36. 

Bark  of  larger  branches  is  reddish-brown,  smooth,  with  scattered, 
small,  round,  dull  straw-colored  lenticels;  twigs  dark  reddish-brown, 
pubescent  when  young,  becoming  glabrous  except  at  the  nodes. 

Leaves. — Larger  leaves  ovate  or  occasionally  oblong,  2L/2  to  4 
inches  long,  1  to  1^2  inches  wide,  truncate  at  base,  obtuse  or  shortly 
acute,  coarsely  and  irregularly  crenate-dentate,  in  some  cases  slightly 
lobed,  persistently  pubescent  below,  becoming  glabrous  above;  there 
are  also  some  small  leaves  nearly  orbicular  in  form  and  irregularly 
bluntly  serrate.  Petioles  %  to  1  inch  long,  stout,  pubescent.  Stipules 
minute,  linear,  more  or  less  persistent.  Flowering  from  terminal  and 
upper  lateral  buds  of  shoots  and  terminal  buds  of  short  spurs.  Of  15 
clusters  examined,  8  had  5  buds  each,  6  had  4  each,  and  1  had  7. 
Buds  globular,  becoming  obovate  as  they  approach  anthesis,  dark 
pink  fading  to  light  pink  as  flowers  open.  Pedicels  rather  short  and 
stout,  bracteate,  densely  pubescent. 

Flowers. — Flower  expands  30  to  35  mm.  Calyx  lobes  5,  rather 
broadly  triangular,  acute,  densely  pubescent  on  both  sides,  closely 
appressed  in  bud,  becoming  acutely  reflexed  in  open  flowers.  Petals  5. 
obovate,  about  15  mm.  long  and  9  mm.  wide,  light  pink;  claw  short 
and  broad.  Stamens  16  to  20,  filaments  slender,  7  mm.  long,  anthers 
large,  plump,  dark  golden-yellow.  Styles  5,  slender,  11  to  12  mm.  in 
length,  free  to  the  base  or  very  nearly  so,  hairy  from  base  up  for 
4  mm.  In  fully  open  flowers  the  styles  have  a  characteristic  red  color. 
Stigmas  round  or  somewhat  irregular,  often  slightly  two-lobed;  when 
young  dark  garnet,  fading  to  the  same  shade  of  red  that  distinguishes 
the  style.  Fig.  46  is  a  twig  in  bud  as  photographed  in  the  greenhouse 
March  19,  1913. 


506 


BULLETIN  No.  275 


[June, 


Fruit. — Oblate,  base  regular,  apex  slightly  irregular,  cross-section 
somewhat  ribbed,  sides  equal,  color  yellow,  a  moderate  amount  of 
waxy  white  bloom;  skin  smooth,  thin,  tough;  a  few  russet  and  many 
white,  small,  round  dots,  the  russet  dots  are  conspicuous,  the  white 

inconspicuous.  Cavity  shallow  to 
medium  in  depth,  acute,  slightly 
ridged,  and  in  some  fruits  lipped. 
Stem  medium  in  length,  about  14 
mm.,  slender,  erect,  green,  pubes- 
cent. Basin  varies  from  shallow 
to  deep,  broad,  obtuse,  slightly 
ribbed.  Calyx  medium  to  small, 
pubescent,  closed  or  half  open; 
core  small,  obcordate,  median, 
closed ;  stamens  median,  core  lines 
clasping;  carpels  obovate,  emargi- 
nate,  somewhat  tufted,  moderately 
concave.  Seeds  plump,  of  medium 
size,  dark  brown.  Flesh  yellowish, 


FIG.  46. — TWIG  OF  MERCER  COUNTY 

CRAB  IN  BUD 

Photographed  in  the  greenhouse 
March  19.  In  flowers  that  are  fully 
open  the  styles  have  a  characteristic 
red  color. 


firm,  rather  dry  and  somewhat 
astringent,  subacid;  quality  poor. 
The  4  fruits  of  1913  developed 
from  flowers  pollinated  with  Yel- 
low Transparent  pollen  March  21 
were  fully  mature  and  ripe  when 

picked  and  described  September  18.  The  single  fruit  of  1914  developed 
from  a  flower  pollinated  with  Grimes  pollen  March  24,  was  picked  and 
described  as  mature  August  22.  This  fruit  was  photographed  July  23, 
1914,  as  it  hung  on  the  twig,  and  appears  in  Fig.  47.  The  average  of 
the  5  fruits  is  a  fruit  weighing  54  grams,  a  vertical  diameter  of  40  mm., 
and  a  transverse  diameter  of  51  mm.  The  average  seed  production  is 
3.4,  which  is  somewhat  below  the  average  for  the  crab  group. 

The  tree  from  which  the  scions  used  by  the  Station  were  taken 
was  received  at  the  Arnold  Arboretum,  as  a  graft,  March  2,  1902,  from 
the  Experiment  Station  at  Brookings,  South  Dakota,  as  the  "Fluke 
Apple."  In  response  to  an  inquiry  regarding  this  crab  Professor  Han- 
sen  of  the  South  Dakota  Station  replies  as  follows, 

"What  the  Arnold  Arboretum  received  from  us  is  evidently  the  Mercer  or 
Fluke  Wild  Crab  itself.  The  late  N.  K.  Fluke  of  Davenport  found  this  growing 
wild  in  Mercer  county,  Illinois.  I  have  been  raising  it  ever  since.  See  tracing  at 
the  end  of  this  letter  which  is  a  print  from  a  specimen  raised  at  this  station  in 
my  fruit  breeding  work.  Early  in  December,  1911,  I  visited  Mercer  county  and 
traced  it  to  the  pasture  where  the  tree  was  found  wild  near  Sherrard,  Illinois, 
but  the  tree  had  been  cleared  off  some  years  previously.  I  also  regret  that  this 
crab  apple  was  not  named  after  Mr.  Fluke  himself  since  Downing  describes  the 
Mercer  apple  of  southern  origin  so  that  the  name  Mercer  is  really  occupied.  It 
may  not  be  too  late  yet  to  name  this  wild  crab  the  Fluke." 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


507 


The  diagram  referred  to  by  Professor  Hansen  accords  perfectly 
with  diagrams  of  fruits  grown  at  the  Illinois  Station,  and  the  crab  now 
growing  as  No.  822  in  the  Illinois  series  doubtless  has  descended  by 
graft  from  the  original  wild  crab  which  Mr.  Fluke  called  the  Mercer 
County  Crab  and  which,  as  suggested  by  Professor  Hansen,  may  with 
propriety  be  called  the  Fluke  Apple. 


FIG.  47. — FRUIT  OF  MERCER  COUNTY  CRAB,  AS 

PHOTOGRAPHED  JULY  23 
This  crab  is  of  the  Soulard  type. 

Further  testimony  regarding  the  origin  of  this  crab  is  found  in  a 
paper  read  before  the  Iowa  State  Horticultural  Society  by  Mr.  N.  K. 
Fluke1  in  1900.  Mr.  Fluke  speaks  of  his  apple  work  as  follows: 

"Ten  years  ago,  having  trees  in  bloom  of  the  Mercer  County  Crab,  which 
is,  no  doubt,  a  natural  variation  of  the  Soulard  type,  and  by  no  means  a  hybrid 
of  Pyrus  Malus,  because  it  was  a  large  tree  and  was  found  growing  in  a  crab 
thicket  far  removed  from  any  cultivated  fruit,  I  pollenized  its  blossoms  with 
pollen  of  Ben  Davis,  Duchess,  Jonathan,  and  Maiden  Blush.  Number  27  (from 
above  work)  fruited  last  year,  is  yellow  in  color,  about  like  medium-sized  Maiden 
Blush;  season  the  first  of  September;  a  fairly  good  eating  apple." 


'Fluke,  N.  K.   Notes  on  the  new  fruits.    Rpt.  Iowa  State  Hort.  Soc.  1900. 


508  BULLETIN  No.  275  [June, 

Craig  and  Hume1  describe  the  Mercer  County  Crab  as  follows: 

"The  fruit  spurs  are  decidedly  like  those  of  Malus  and  thorns  do  not  occur. 
.  .  .  Irregularities  in  leaf  characteristics,  vigorous  growth,  diminution  of  repro- 
ductiveness,  all  indicative  of  hybridity,  are  present,  and  we  give  it  as  our  opinion 
that  this  crab  is  the  result  of  a  cross  of  Malus  and  lowensis.  The  seeds  average 
3.1  to-  the  apple.  .  .  .  This  crab  originated  in  Mercer  county,  Illinois,  and  was 
introduced  by  N.  K.  Fluke  of  Davenport,  Iowa." 

Experience  regarding  the  breeding  qualities  of  this  crab  is  too 
limited  to  warrant  an  opinion  as  to  its  possibilities,  as  the  only  pollin- 
ations have  been  upon  the  one  dwarf  tree  in  the  greenhouse.  With  this 
one  individual  the  results  have  not  been  such  as  to  arouse  enthusiasm. 
In  1913,  11  flowers  pollinated  by  Yellow  Transparent  gave  4  fruits 
which  contained  14  seeds,  9  of  which  germinated;  only  one  weak  tree 
survived,  made  a  feeble  growth  in  the  two  following  years,  and  then 
died.  The  following  year  9  flowers  pollinated  by  Grimes  gave  1  fruit 
containing  3  seeds,  one  of  which  germinated,  but  the  seedling  died  the 
first  season.  In  1916,  the  34  pollinations  made  by  Grimes,  Jonathan, 
and  Akin  all  failed;  for  the  next  year  23  flowers  pollinated  by  Fanny 
matured  1  fruit  containing  3  seeds,  none  of  which  germinated.  Again 
in  1918,  Yellow  Transparent  pollen  was  used  on  4  flowers,  but  no 
fruits  matured.  The  net  result,  then,  from  81  pollinations  in  the  five 
years  is  entire  failure.  This  is  not  an  encouraging  record.  When  pol- 
linations can  be  made  on  a  more  extensive  scale  it  is  hoped  better 
results  may  be  attained.  In  1914  pollen  of  the  Fluke  apple  was  used 
in  23  pollinations  on  M.  ringo;  11  fruits  matured,  25  seeds  were 
planted,  13  germinated,  and  2  seedlings  now  in  their  tenth  year  are  in 
orchard;  one  of  these  is  8  feet  10  inches  high,  has  a  spread  of  7  feet 
5  inches,  a  trunk  diameter  of  3.1  inches,  and  is  graded  as  "good."  The 
other  is  3%  feet  high,  spreads  2  feet  3  inches,  has  a  trunk  diameter  of 
.7  inch,  and  is  graded  as  "poor."  These  are  the  only  hybrids  in  which 
the  Fluke  apple  appears  as  one  of  the  parents. 

23.  Malus  mains  441/1  (829) 

The  scions  were  received  from  the  Arnold  Arboretum  in  January, 
1908,  and  were  taken  from  a  tree  grown  at  the  Arnold  Arboretum  from 
seed  received  from  Bavaria  in  1889  under  the  name  Pyrus  Malus  L. 
From  an  examination  of  herbarium  specimens  it  is  scarcely  possible  to 
distinguish  it  from  Malus  pumila  of  Europe  or  from  certain  forms  of 
Malus  sylvestris.  Three  trees  were  planted  in  orchard  in  1910  from 
root-grafts  made  January  18,  1908.  These  trees  have  grown  rather 
slowly.  They  are  symmetrical  and  in  the  first  years  very  erect;  in 
later  years  they  have  become  somewhat  spreading.  As  measured  in 


JCraig  and  Hume.    Native  crab  apples  and  their  cultivated  varieties.    Iowa 
Acad.  Sci.    7,  139.    1899. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  509 

1923  the  height  was  14  feet  2  inches,  spread  15  feet  9  inches,  and 
trunk  diameter  5.6  inches.  The  trunks  are  2  feet  long  with  smooth, 
dark  olive-brown  bark;  above,  the  branches  are  numerous  and  the 
foliage  dense. 

Leaves. — Ovate  or  oblong  2  to  5  inches  long;  1  to  2%  inches  wide, 
coarsely  and  irregularly  dentate  or  toward  the  apex  serrate,  acute  or 
obtuse,  glabrous  above,  pubescent  along  midrib  and  veins  below. 
Petioles  stout,  %  to  1%  inches  long,  pubescent.  In  general  appearance 
the  trees  are  strikingly  like  small  trees  of  the  common  apple.  In  1911 
scions  from  one  of  the  trees  were  worked  on  paradise  stocks  growing 
in  pots;  these  dwarfs  have  been  forced  under  glass  each  spring  since. 
The  species  was  also  top-worked  on  a  Grimes  in  1912  and  has  formed 
a  round  symmetrical  top. 

In  the  spring  of  1917,  2  flower  clusters  were  borne  by  the  top- 
worked  tree  and  from  one  of  these  the  following  flower  description  was 
made.  Cluster  of  6  buds  terminal  on  a  4-inch  spur.  Leaves  from  the 
mixed  bud  ovate  to  oblong,  1  to  2  inches  long  and  l/2  to  %  mcn  wide, 
crenate-serrate,  acute,  pubescent  along  the  veins  above,  lower  surface 
covered  with  a  fine,  close  pubescence.  Petioles  %  mcn  l°ng>  pubescent. 
Buds  umbellate,  opening  nearly  together,  pink.  Pedicels  stout,  15  mm. 
long,  pubescent,  tinged  brown,  bracteate ;  ovary  pubescent,  green  or  in 
part  brownish.  Calyx  lobes  5,  triangular  acuminate,  7  mm.  long,  3% 
mm.  wide  at  base,  pubescent  both  sides. 

Flowers. — Expand  40  mm.  Petals  oval,  17  mm.  long  by  14  mm. 
wide,  with  short  claw;  fading  to  nearly  white,  but  many  retain  small 
light  pink  spots  outside.  Stamens  20,  filaments  slender,  5  to  9  mm. 
long;  anthers  plump,  light  creamy  yellow.  Styles  5,  slender,  flattened 
at  tips,  10  mm.  in  length,  connate  for  2  mm.  up  from  base,  glabrous 
at  base;  a  few  short  hairs  about  the  point  of  separation;  stigmas  irreg- 
ularly oval. 

In  the  spring  of  1918,  on  one  of  the  dwarfs  in  greenhouse,  5  flowers 
were  pollinated  by  Delicious;  1  fruit  containing  9  seeds  matured; 
7  of  the  seeds  germinated  and  five  seedlings  now  in  their  sixth  year  are 
in  orchard.  These  seedlings  are  much  alike,  they  average  5  feet  high, 
4  feet  3  inches  in  spread,  and  1  inch  in  diameter. 

Fruit. — Description  of  the  1  fruit  from  this  cross  is  as  follows: 
Weight  88.7  gms.,  vertical  diameter  54  mm.,  transverse  diameter  63 
mm.;  oblate-roundish,  base  irregular,  apex  irregular,  slightly  conical, 
cross-section  irregular,  ribbed,  sides  equal;  size  medium;  ground  color 
green,  faintly  striped  and  the  surface  mostly  covered  with  dull  light 
red,  bloom  medium,  waxy,  white;  skin  smooth,  tough,  of  medium 
thickness;  dots  many,  small,  round,  white,  inconspicuous;  cavity  me- 
dium in  depth  and  width,  acute,  regular;  stem  40  mm.  in  length,  slen- 
der, erect,  green,  pubescent;  calyx  small,  pubescent,  closed.  Basin 


510  BULLETIN  No.  275  [June, 

deep,  acuminate,  irregular,  ribbed;  calyx  lobes  small,  long-slender, 
acuminate,  reflexed,  calyx  tube  conical,  of  medium  size;  core  medium, 
cordate,  median,  closed,  cells  axile,  uniform;  carpels  ovate,  emarginate, 
tufted,  concave;  flesh  yellowish,  tender,  dry,  mealy,  subacid,  quality 
poor,  flat,  and  without  distinctive  flavor. 

24.  Mains  mains  var.  (830) 

Number  830  is  represented  by  three  trees  which  are  now  in 
their  tenth  year  from  root-grafts  made  with  scions  from  the  Arnold 
Arboretum  in  January,  1908,  one  tree  on  paradise  in  pot  from  scion 
inserted  in  February,  1910,  and  four  trees  from  root-grafts  made  in 
1914.  The  dwarf  tree  flowered  and  fruited  in  1914;  the  older  trees  in 
orchard  in  1916.  Trees  erect,  dwarfish  in  habit,  branches  numerous, 
producing  many  short  blunt  spurs.  The  older  trees  are  now  10  feet 
high  with  a  spread  of  8  feet  and  an  average  trunk  diameter  of  2.4 
inches. 

Leaves. — Large,  thick,  leathery,  3  to  5  inches  long,  1  to  2%  inches 
wide,  ovate  or  oblong  or  some  of  the  smaller  lanceolate,  acute  or  acu- 
minate, crenate-dentate,  glabrous  thruout.  Petioles  stout,  medium  in 
length  to  short. 

Flowers. — Produced  from  terminal  buds  of  spurs  and  from  ses- 
sile lateral  buds.  Young  buds  globular,  deep  red,  becoming  oblong  and 
light  pink.  Open  flowers  are  nearly  pure  white,  only  slight  tinges  of 
pink  remaining,  expanding  35  mm.  Pedicels  slender,  30  mm.  long,  gla- 
brous, bracteate.  Calyx  lobes  5,  narrowly  triangular,  acuminate,  gla- 
brous outside,  pubescent  inside.  Petals  large,  ovate  to  oblong,  rounded 
at  apex,  18  mm.  long,  13  mm.  wide,  claw  2  mm.  in  length.  Stamens 
usually  20;  the  numbers  as  counted  for  26  flowers  were  as  follows; 
18  flowers  had  20  each,  3  had  19  each,  2  had  18  each,  2  had  17  each, 
and  1  had  16;  filaments  slender,  5  to  8  mm.  long,  anthers  plump,  light 
yellow,  pollen  abundant,  dark  orange  at  time  of  dehiscence.  Styles  5, 
slender,  8  mm.  long,  connate  one-third  length,  glabrous  immediately  at 
base,  then  hairy  to  just  above  the  point  of  separation;  stigmas  oval, 
oblique. 

Leaves  are  somewhat  in  advance  of  flowers  so  that  the  trees  are 
very  leafy  when  the  flowers  open.  The  light  green  of  the  leaves  and 
the  nearly  white  blossoms  on  long  pedicels  present  a  handsome  ap- 
pearance. Fig.  48  from  photograph  of  a  terminal  twig  taken  in  the 
greenhouse  February  24,  1917,  shows  the  relative  development  of 
leaves  and  flower  buds  from  a  terminal  mixed  bud. 

Fruit. — Roundish,  slightly  oblate,  quite  uniform  in  shape,  but  not 
in  size.  Of  41  fruits  the  minimum  weight  is  5.15  grams,  the  maximum 
31.15  grams  with  an  average  of  16.77  grams.  Vertical  diameters  range 
between  18  and  34  mm.,  with  an  average  of  27  mm.;  transverse  diam- 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  511 

eters  range  between  22  and  42  mm.,  with  an  average  of  33  mm. 
Ground  color  yellow  overlaid  with  red  which  varies  from  light  to  me- 
dium in  shade,  skin  smooth,  thin,  tough ;  dots  few,  large,  white,  incon- 
spicuous. Calyx  lobes  deciduous  in  all  fruits;  core  medium  size  cord- 
ate, median,  closed;  cells  axile;  carpels  roundish,  obovate,  entire,  gla- 
brous; flesh  yellowish,  firm,  rather  dry,  acid.  In  general  appearance 
of  tree  and  foliage  this  form  resembles  M.  pumila  or  a  dwarf  form 


FIG.  48. — TWIG  OF  M .  mains  VAR.  (830)  SHOWING  RELATIVE  DEVELOP- 
MENT OF  LEAVES  AND  FLOWER  BUDS.     FIG.  49. — MATURE 

FRUIT  PHOTOGRAPHED  SEPTEMBER  1 1 ,  NATURAL  SIZE 
Leaves  are  somewhat  in  advance  of  flowers  in  this  species,  so 
that  the  trees  are  very  leafy  when  the  flowers  open.    The  leaves 
are  light  green  and  the  blossoms,  which  are  almost  white,  are  on 
long  pedicels. 


of  M.  sylvestris,  but  the  long  slender  pedicels  and  the  regularly  de- 
ciduous calyx  suggest  the  baccata  group.  It  is  probable  that  this  vari- 
ety is  a  hybrid  between  one  of  the  many  forms  of  M.  mains  and 
some  form  of  M.  baccata.  Fig.  49  shows  a  single  fruit  natural  size, 
as  developed  from  a  flower,  on  an  orchard  tree,  pollinated  by  Ben 
Davis  May  8  and  photographed  at  maturity  September  11,  1916.  In 
Fig.  50  is  shown  a  cluster  of  fruits  natural  size,  developed  under  the 
cross  number  of  11428  from  flowers  on  a  dwarf  tree  in  the  greenhouse 
pollinated  February  28;  picked,  described,  and  photographed  July  10, 
1917.  This  form  of  Malus  has  been  used  as  the  female  parent  in  six 
crosses.  The  cross  by  Domine  failed;  those  by  Ben  Davis,  Yellow 
Transparent,  Yellow  Siberian  Crab  (857),  M.  prunifolia  var.  (19651), 
and  M.  niedwietzkyana  (834)  were  successful  in  percentages  varying 
from  1  to  nearly  90.  These  crosses  are  represented  in  orchard  by  165 


512 


BULLETIN  No.  275 


[June, 


seedlings  from  3  to  7  years  old.  As  a  male  parent  it  has  been  used  in  5 
crosses.  On  flowers  of  Yellow  Siberian  Crab  (857)  no  fruits  devel- 
oped; on  M.  mains  var.  (19667)  and  M.  prunifolia  xanthocarpa,  there 
were  4  fruits  in  each  cross,  but  seeds  failed  to  germinate;  only  two 
crosses  are  represented  in  orchard,  one  on  M.  prunifolia  var.  (19651) 


FIG.  50. — CLUSTER  OF  FRUITS  OF  M.  Mains  VAR.  (830),  NATURAL  SIZE 
Developed  from  flowers  on  dwarf  tree  in  the  green  house  pollinated  by 
M.  niedwietzkyana  February  28,   1917;   picked  and  photographed  July   10, 
1917.   Seventeen  fruits  were  matured  from  19  pollinations. 


by  ten  seedlings  and  the  other  on  M.  baccata  oblonga  by  nineteen 
seedlings ;  the  seedlings  vary  in  age  from  seven  to  ten  years. 

25.  Mains  mains  var.  (19667) 

Scions  from  Arnold  Arboretum  received  in  January,  1907,  thru 
the  U.  S.  Department  of  Agriculture  under  the  number  of  19667  and 
carried  in  the  Station  collection  as  one  of  the  19000  series  under  the 
same  number.  At  present  represented  by  one  tree  from  root-graft,  on' 
ordinary  apple  stock,  made  March  23,  1907,  and  now  seventeen  years 
old,  six  trees  from  root-grafts,  on  apple  stocks  made  February  29, 
1912,  and  now  in  orchard  on  the  Douglas  tract,  one  tree  top-worked  on 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


513 


a  Higby  Sweet  March  18,  1912,  three  trees  on  paradise  stocks  grafted 
March  5,  1913,  and  forced  each  year  since  under  glass,  and  four  trees 
from  root-grafts  made  January  22,  1914,  and  now  in  orchard  on  the 
south  tract. 


FIG.  51. — TREE  OF  M.  mains  VAR.  (19667)   FROM  ROOT-GRAFT 
MADE  MARCH  23,  1907,  AS  IT  APPEARED  OCTOBER  2,  1915 
This  tree  is  spreading  in  habit,  and  straggling  branches  make 
the   general   outline    of   the   crown    irregular.    The    bark   of   the 
smooth  trunk  is  greenish-brown,  the  branches  dark  olive-green, 
and  the  twigs  reddish-brown. 

Habit  of  growth  is  best  shown  in  the  root-graft  of  1907.  This  tree 
is  now  17  years  from  graft,  14  feet  6  inches  high,  has  a  spread  of  12 
feet  10  inches,  and  a  trunk  diameter  of  5.2  inches.  Its  habit  is  spread- 
ing, some  branches  are  straggling,  and  the  general  outline  of  the  crown 
irregular.  Bark  of  the  smooth  trunk  is  greenish-brown,  branches  dark 


514  BULLETIN  No.  275  [June, 

olive-green  and  twigs  reddish-brown.  This  tree  as  it  appeared  when 
photographed  October  2,  1915,  is  shown  in  Fig.  51. 

Leaves. — Those  on  flowering  shoots  are  orbicular,  oblong,  obovate 
or  sometimes  lanceolate,  1  to  3l/2  inches  long,  acute,  sharply  serrate; 
on  non-flowering  shoots  elliptical,  oval,  or  oblong,  4  to  5  inches  long 
and  2  to  2%  inches  wide,  acute  or  acuminate,  coarsely  doubly-dentate. 
All  are  pubescent  below  and  are  more  or  less  covered  with  scattered 
hairs  above  when  young;  later  they  are  glabrous  above.  Petioles 
pubescent,  those  from  mixed  buds  are  long  and  slender,  from  lateral 
buds  of  non-flowering  shoots  shorter  and  much  more  robust. 

Flowers. — A  few  clusters  of  flowers  from  terminal  buds  of  short 
interior  spurs  were  produced  in  1913;  in  succeeding  years  the  amount 
of  bloom  has  increased  and  comes  both  from  terminal  buds  of  short 
spurs  and  from  terminal  and  lateral  buds  of  shoots  of  the  preceding 
year.  The  internodes  of  terminal  shoots  are  rather  long,  separating  the 
bud  clusters  so  that  they  do  not  appear  crowded;  the  flowering  por- 
tion of  shoots  varies  from  3  or  4  to  8  or  10  inches  long.  Flowers  and 
leaves  come  together,  but  the  pedicels  are  so  long  that  the  flowers  are 
conspicuous.  There  is  wider  range  in  number  of  flowers  to  the  cluster 
than  is  found  in  other  forms;  the  138  clusters  counted  gave  distribu- 
tion as  follows: 

With    3  buds  each , 4 

With    4  buds  each 3 

With    5  buds  each 8 

With    6  buds  each :  .39 

With    7  buds  each 55 

With    8  buds  each 21 

With    9  buds  each 6 

With  10  buds  each 2 

Young  buds  are  globular  and  very  deep  red,  they  become  elong- 
ated as  petals  increase  in  size  and  the  color  fades  to  shades  of  pink; 
fully  open  flowers  retain  but  a  trace  of  the  pink  color.  Flowers  expand 
23  to  28  mm.  Pedicels  slender,  pubescent,  40  to  57  mm.  long  in  upper 
clusters,  30  to  40  mm.  long  in  lower,  smaller  clusters,  ovaries  pubes- 
cent. Calyx  lobes  5,  triangular,  acute,  about  3  mm.  long,  pubescent 
both  sides,  erect  in  bud,  tips  becoming  reflexed  in  open  flowers.  Petals 
5,  oval  to  oblong,  rounded  at  apex,  tapering  to  a  very  short  claw,  20 
mm.  long,  15  mm.  wide.  Stamens,  as  determined  from  examination  of 
75  buds,  vary  in  number  from  17  to  31  with  an  average  a  little  above 
23;  filaments  slender,  6  to  9  mm.  long,  white;  anthers  plump,  light 
yellow.  Styles  5,  or  occasionally  6,  slender,  7  mm.  long,  connate  % 
the  length  and  hairy  from  base  to  above  the  point  of  separation. 
Stigmas  oval,  capitate. 

Fruit. — Round  or  slightly  oblate,  base  regular,  apex  somewhat 
ribbed,  cross-section  sometimes  obscurely  ribbed,  sides  often  somewhat 
unequal.  Weight  and  dimensions  have  been  determined  for  two  dis- 


1926] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


515 


tinct  lots  of  the  fruits  of  this  form  of  Malus.  A  lot  of  221  fruits 
developed  from  flowers  open  to  pollination  by  insects  and  from  which 
the  following  averages  were  obtained:  weight  5.92  grams,  longitudinal 
diameter  19  mm.,  transverse  diameter  21  mm.,  and  number  of  seeds  to 
each  fruit  3.77.  A  further  lot  of  215  fruits  developed  from  protected 
hand-pollinated  flowers  gave  ex- 
actly the  same  average  diameters, 
but  the  average  weight  is  4.9 
grams  and  the  average  number  of 
seeds  4.10.  It  is  not  held,  however, 
that  the  difference  in  manner  of 
pollination  is  accountable  for  the 
decreased  weight  or  the  increased 
seed  production  in  the  lot  from 
hand-pollinated  flowers.  Were  the 
results  here  shown  similar  for  oth- 
er groups  of  other  forms  of  Malus 
it  might  be  assumed  that  manner 
of  pollination  was  the  direct  cause 
of  the  differences,  but  results  are 
not  in  the  least  uniform;  they 
vary  greatly  and  in  both  direc- 
tions. Probably  the  differences 
appearing  are  not  greater  than 
might  reasonably  be  expected 
from  entirely  distinct  lots.  It  is  an 
interesting  coincidence,  however, 
that  the  diameters  of  the  two  lots 
are  identical,  and  this  adds  stabil- 
ity to  the  averages  for  these  di- 
mensions. The  ground  color  of  the 


FIG.  52. — FRUITING  BRANCH  OF 

M.  mains  VAR.  (19667) 
The  ground  color  of  this  fruit  is  a 
clear  yellow,  with  the  over-color  a 
bright  red.  In  tree  characters  this 
form  of  Malus  resembles  M.  sylves- 
tris,  but  the  fruit  characters  are  those 
of  the  baccata  group. 


fruit  of  this  form  is  a  clear  yellow, 
the  over  color  bright,  light  to  me- 
dium red;  bloom  scant,  waxy, 
gray;  skin  smooth,  polished,  thin, 
tough.  Cavity  medium  in  depth, 
rather  broad,  regular,  rounded. 
Stem  very  long,  slender,  clavate, 

erect,  green,  pubescent.  Calyx  deciduous  in  most  fruits;  of  248  fruits 
examined  201,  or  81  percent,  had  deciduous  calyx  lobes,  while  for  47, 
or  19  percent,  the  lobes  were  persistent;  basin  shallow,  rather  broad, 
obtuse,  irregularly  ribbed ;  core  of  medium  size,  oblate,  median,  closed ; 
carpels  roundish,  emarginate,  glabrous,  moderately  concave.  Seeds  are 
plump,  above  medium  in  size,  long-pointed,  rather  dark  brown;  flesh 
yellowish,  firm,  juicy,  very  acid.  A  fruiting  twig  as  photographed  Sep- 


516 


BULLETIN  No.  275 


[June, 


FIG.  53. — FRUIT  CLUSTER  OF  M.  mains  VAR.  (19667) 
This  single  cluster  is  from  one  of  the  dwarf  trees  in  pots: 
the  flowers  were  pollinated  with  Oldenburg  pollen  on  March  28, 
1914,  and  the  photograph  of  the  fruit  was  taken  July  30  of  the 
same  year. 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


517 


tember  15,  1915,  is  shown  in  Fig.  52  and  a  single  cluster  in  Fig.  53. 
This  single  cluster  is  from  one  of  the  dwarf  trees  in  pots;  flowers  of  the 
cluster  were  pollinated  with  Oldenburg  pollen  on  March  28  and  photo- 
graph of  the  fruit  was  taken  July  30,  1914.  See  also  a  single  fruit  of 
this  form  of  Malus  below  at  the  right  in  Fig.  54.  In  tree  characters  this 


FIG.  54. — FRUITS  OF  FOUR  OF  THE  CRAB  FORMS  OF  MALUS 
Above:    M.    ringo    sublobata    (19689).     Below,    left    to    right: 
M.  prunijolia  var.   (19651),  M.  microcarpa   (19644),  M.  mains  var. 
(19667). 


form  of  Malus  resembles  M.  sylvestris,  but  the  fruit  characters  are 
those  of  the  baccata  group.  It  is  quite  probable  that  it  is  a  hybrid 
between  a  form  of  sylvestris  and  a  form  of  baccata  or  it  may  be  a 
combination  of  M.  prunijolia  and  M .  baccata. 

The  tree  has  merit  as  an  ornamental  altho  it  does  not  present  such 
dense  masses  of  flowers  as  characterize  some  other  forms.  The  fruit  is 
handsome  and  commonly  persists  until  late  in  October.  It  propagates 
readily,  is  adapted  to  forcing,  and  controlled  pollination  of  flowers  has 
been  exceptionally  successful. 

M.  mains  var.  (19667)  has  served  as  female  in  23  crosses  by  9 
orchard  varieties  and  4  crab  forms.  Three  of  the  crosses  produced  no 
fruits,  3  bore  fruits  with  seeds,  but  the  seeds  failed  to  germinate, 
1  germinated  one  seed  but  the  seedling  did  not  live.  Of  the  others 
3  were  by  Yellow  Transparent  with  53  as  the  aggregate  of  pollina- 


518  BULLETIN  No.  275  [June, 

tions,  maturing  30  fruits  and  now  represented  by  65  trees  in  orchard, 
8  to  10  years  old.  Oldenburg  pollen  was  used  in  4  crosses  with  194 
pollinations  yielding  78  fruits,  and  these  crosses  are  represented  in 
orchard  by  168  seedlings.  Jonathan  pollen  was  used  in  2  crosses 
with  219  pollinations  maturing  47  fruits  and  represented  in  orchard  by 
110  seedlings.  The  remaining  pollen  parents  and  the  number  of  seed- 
lings representing  each  cross  are  as  follows:  Maiden  Blush  2;  Domine 
2;  Grimes  5;  Oliver  13;  Sops  of  Wine  80;  Sweet  Bough  109. 

The  aggregate  of  pollinations  in  the  23  crosses  was  948;  number 
of  fruits  matured  307,  giving  32.88  percent  as  the  degree  of  success. 
This  is  based  simply  on  fruits  matured  and  takes  no  account  of  seed- 
less fruits,  or  fruits  whose  seeds  did  not  germinate,  or  of  fruits  pro- 
ducing seedlings  too  weak  to  live.  Similar  success  percentage  for  the 
aggregate  of  all  crosses  made  is  approximately  24  percent;  hence  the 
percentage  of  success  given  for  the  group  of  crosses  in  which  the  Malus 
under  consideration  served  as  the  female  parent  may  be  considered  as 
sufficiently  high  to  rate  the  plant  as  a  good  breeder.  Use  as  the  pollen 
parent  was  much  less  successful;  10  crosses  were  made  on  six  varieties 
and  the  Soulard  Crab,  7  failed  and  the  other  3  were  not  highly 
successful;  2  crosses  on  Oldenburg  with  17  pollinations,  matured  3 
fruits,  and  1  cross  on  Grimes  with  50  pollinations  yielded  17  fruits. 
For  the  10  crosses  there  were  140  pollinations  maturing  20  fruits,  indi- 
cating 14.28  percent  as  the  success  percentage,  a  very  low  rate  of 
success.  Apparently  this  form  of  Malus  is  more  successful  as  a  pistil- 
late parent  than  as  a  pollen  parent. 

26.  Malus  mains  var.  pendula  (832,  19688) 

Represented  in  the  collection  under  the  number  19688  as  root- 
grafted  trees  from  scions  received  in  1907  from  the  Department  of 
Agriculture ;  and  also  under  number  832  as  both  root-grafted  and  top- 
grafted  trees  from  scions  from  the  Arnold  Arboretum  in  1908.  All 
trees  have  a  decidedly  pendulous  habit;  the  top-grafts  have  grown 
with  a  fair  degree  of  vigor;  root-grafts  grew  slowly  during  the  first 
three  or  four  years,  but  later  exhibited  a  degree  of  vigor  equalling  the 
top-grafts.  Branches  of  the  root-grafted  trees  trail  close  to  or  directly 
on  the  ground;  a  tree  eleven  years  from  the  graft  had  dimensions  as 
follows:  extreme  height  3  feet  10  inches,  greatest  spread,  10  feet  10 
inches,  and  trunk  diameter  3.2  inches.  This  tree  as  photographed  July 
11,  1916,  is  shown  in  Fig.  55.  The  drooping  habit  precludes  root-graft- 
ing as  a  method  of  propagation;  the  form  is  only  adapted  to  high  top- 
working.  The  habit  of  a  tree,  top-worked  in  March,  1908,  is  shown 
in  Fig.  56  as  photographed  October  26,  1911.  This  drooping  form 
commends  itself  only  as  a  curiosity;  it  has  no  economic  value.  Bark 
light  gray  with  a  tinge  of  olive-green;  twigs  reddish-brown,  but  ap- 
pearing light  gray,  because  of  the  dense,  close  pubescence. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  519 

Leaves. — Coarse,  dark  green,  3%  to  5%  inches  long,  1  to  2  inches 
wide,  coarsely  crenate-dentate,  acuminate,  densely  tomentose  below, 
becoming  glabrous  above;  petioles  short,  stout,  covered  with  a  dense 
persistent  tomentum.  Stipules  small,  linear  or  lanceolate,  petioled, 
mostly  persistent. 

Flowers. — From  terminal  buds  of  twigs  of  the  preceding  year,  in 
clusters  of  6.  Buds  light  pink  fading  to  white  as  flowers  open.  Flowers 


FIG.  55. — TREE  OF  M.  mains  pendula  (832)  IN  ITS 

NINTH  YEAR  FROM  ROOT-GRAFT 

All  trees  of  this  variety  show  a  decided  tendency  to  droop; 
branches  of  the  root -grafted  trees  trail  close  to  or  directly  on  the 
ground.  Obviously  this  form  is  only  adapted  to  high  top-working 
as  a  method  of  propagation. 


expand  45  mm.  Calyx  lobes  5,  broadly  triangular,  acute,  7  mm.  long, 
3  mm.  wide  at  base,  densely  tomentose  on  both  sides,  reflexed  in  open 
flowers.  Petals  5,  oval  in  form,  20  mm.  long,  14  mm.  wide  with  claw 
2  mm.  in  length.  Stamens  range  in  number  from  15  to  22  with  an 
average  of  18,  filaments  slender,  4  to  8  mm.  long,  anthers  plump,  light 
yellow.  Styles  4  or  5,  slender,  8  to  11  mm.  long,  connate  one-third 
length  and  densely  hairy  from  base  to  above  the  point  of  separation; 
stigmas  oval,  oblique. 

Fruit. — Round  or  slightly  oblate,  more  or  less  irregular  at  base 
and  apex  and  in  cross-section  somewhat  ribbed,  sides  unequal,  size 
medium;  as  averaged  from  3  fruits  the  weight  is  122  grams,  longitud- 
inal diameter  60  mm.  and  transverse  diameter  68  mm.  The  ground 
color  is  green,  blushed  and  irregularly  striped  with  medium  red  which 


520 


BULLETIN  No.  275 


[June, 


in  spots  becomes  quite  dark,  covered  with  a  waxy  bloom  which  has  a 
purplish  tinge;  skin  smooth,  of  medium  thickness,  tough,  dots  many, 
irregular,  or  round,  white,  conspicuous.  Cavity  of  medium  depth, 

medium  in  width,  acute, 
regular;  stem  short,  8  to 
10  mm.  long,  slender, 
clavate,  erect,  green,  pu- 
bescent. Calyx  of  me- 
dium size,  pubescent, 
closed;  basin  medium  in 
depth  and  breadth, 
acute,  irregular,  ribbed; 
calyx  tube  of  medium 
size,  conical.  Core  cor- 
date, of  medium  size, 
median,  closed  or  some- 
times half  open;  stamens 
median,  core  lines  clasp- 
ing; carpels  elliptical  or 
obovate,  entire,  tuft- 
ed, moderately  concave. 
Seeds  plump,  of  medium 
size,  dark  colored;  flesh 
white,  firm,  crisp,  juicy, 
subacid,  of  good  flavor. 
Season  late  September. 
Two  fruits  somewhat  be- 
low average  size,  but  photographed  natural  size,  are  shown  in  Fig.  57. 

27.  Mains  microcarpa  (19644) 

Scions  from  the  Arnold  Arboretum  were  received  thru  U.  S. 
Department  of  Agriculture  in  January,  1907,  and  root-  and  top-grafts 
were  made  under  the  accession  number  19644,  which  is  retained  for 
plants  in  the  Station  collection.  There  is  a  tree  from  graft  on  Doucin 
in  1910  that  has  flowered  under  glass  each  year  since  1913.  A  twig 
from  this  dwarf  tree,  in  bud  as  photographed  March  12,  1913,  appears 
in  Fig.  58,  and  Fig.  59  shows  the  appearance  of  the  top-worked  tree  in 
October,  1916,  five  years  from  insertion  of  the  scions.  When  young 
M.  microcarpa  is  strictly  erect  in  habit  with  numerous  branches 
which  all  grow  straight  up.  As  the  tree  gets  older  the  branches  become 
ascending  and  by  the  twelfth  year  they  are  distinctly  spreading. 

A  tree  top-worked  in  1912  now  measures  14  feet  5  inches  in 
height,  18  feet  6  inches  in  spread,  and  6.2  inches  in  diameter  of  trunk. 


FIG.     56. — TOP-WORKED     TREE    OF     M.    malus 
pendula  (832)  THREE  YEARS  FROM  IN- 
SERTION OF  THE  SCIONS 

The  drooping  form  of  this  species,  even 
when  top-worked,  makes  it  of  no  value  except 
as  a  curiosity. 


1926] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


521 


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522 


BULLETIN  No.  275 


[June, 


A  root-graft  of  1907  lacks  2  inches  of  being  18  feet  high,  is  19  feet  4 
inches  in  spread,  and  6.7  inches  in  diameter  of  trunk. 

Bark  of  the  trunk  dark  brown,  branches  olive-green  and  twigs 
reddish-brown.  Shoots  of  the  season  are  still  somewhat  pubescent  at 
the  tips  in  October.  Lenticels  are  few  and  inconspicuous.  Habit  of 


FIG.    58. — TWIG    OF    TREE    OF    M.    microcarpa 

(19644)    IN    BUD    ON    DWARF    STOCK    IN 

GREENHOUSE,  AS  PHOTOGRAPHED 

MARCH  12,  1913 

In  this  species,  a  large  proportion  of  the 
flowers  are  borne  from  terminal  buds  of  short 
spurs,  but  there  are  also  small  masses  of  flow- 
ers appearing  from  terminal  and  lateral  buds 
of  terminal  shoots. 

growth,  especially  as  regards  trend  of  branches  and  tendency  to  pro- 
duction of  short  spurs,  is  shown  in  Fig.  60,  from  photograph  taken 
during  the  dormant  season  of  a  tree  seven  years  old  from  root-graft. 

Leaves. — Variable  in  size;  on  lower  and  interior  shoots  they  are 
from  1  to  3l/2  inches  long,  ovate  or  lanceolate;  on  rampant  terminal 
shoots  they  range  from  3  to  4%  inches  in  length,  are  broadly  ovate  or 
nearly  orbicular,  acute,  irregularly  crenate-dentate;  glabrous  above 
and  sparingly  pubescent  below.  Petioles  %  to  1%  inches  in  length, 
stout,  pubescent.  Stipules  which  are  long  persistent  on  some  leaves  are 
small,  lanceolate,  petioled. 

Flowers. — A  graft  of  1912  began  flowering  in  1916,  and  with  the 
exception  of  1917  has  bloomed  each  year  since.  The  earliest  date  for 
full  bloom  was  April  15  in  1921,  while  May  10  in  1920  was  the  latest 
date.  May  1  is  the  mean  date  for  an  average  of  eight  years.  A  large 


19261 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


523 


proportion  of  the  flowers  are  borne  from  terminal  buds  of  short  spurs, 
but  there  are  also  small  masses  from  terminal  and  lateral  buds  of 
terminal  shoots.  Most  flower  clusters  have  6  buds  each,  a  few  have  5 
or  7,  and  one  had  a  single  bud.  Bud  clusters  are  compact  and  show 
considerable  differences  in  advancement,  terminal  clusters  start  earlier 


FIG.    59. — TOP-WORKED    TREE    OF    M.    micro- 
carpa  (19644)  FIVE  YEARS  FROM  GRAFTING 
The  tree  of  this  species  is  strictly  erect  in 
habit  when  young,  the  branches  all   growing 
straight  up.     By  the  time  the  tree  is  twelve 
years  old,  however,  the  branches  are  distinctly 
spreading. 

and  advance  more  rapidly  than  do  those  from  lateral  buds.  The  flower 
expands  25  mm.  Calyx  lobes  narrowly  triangular,  acuminate,  pubes- 
cent both  sides,  petals  in  unopened  buds  dull  pink,  becoming  white  as 
the  flower  opens,  obovate  to  oblong,  rounded  at  apex,  rather  abruptly 
contracted  to  the  very  short  claw.  Stamens  vary  in  number  from  17 
to  21,  filaments  slender,  varying  in  length  from  4  to  10  mm.,  anthers 
plump,  light  yellow.  Styles  5  in  most  flowers,  but  those  having  3  or  4 
are  not  rare,  8  to  10  mm.  long,  connate  %  the  length  and  slightly 
hairy  from  base  to  middle,  stigmas  sometimes  capitate,  sometimes 
oval,  oblique. 


524 


BULLETIN  No.  275 


[June, 


Fruit.^-The  fruit  is  round  or  slightly  oblate;  312  fruits  weighed 
and  measured  gave  an  average  weight  of  7.32  grams,  a  vertical 
diameter  of  21  mm.,  and  a  transverse  diameter  of  25  mm.  The 
seed  average  is  5.8,  which  is  above  the  average  for  fruits  of  the  crab 
group.  Base  and  apex  are  regular,  ground  color  yellow  blushed  light 


FIG.  60. — TREE  OF  M.  microcarpa   (19644) 
SEVEN  YEARS  FROM  ROOT-GRAFT,  SHOW- 
ING  TREND   OF   BRANCHES   AND 
NUMEROUS  SHORT  SPURS 


red  indistinctly  striped  with  dark  red.  Bloom  moderately  heavy,  waxy, 
purple;  skin  smooth,  thin,  tough;  dots  few,  irregular,  areolar,  russet, 
conspicuous.  Cavity  medium  in  depth,  rather  broad,  acuminate,  regu- 
lar; stem  short,  8  to  14  mm.  long,  slender,  clavate,  erect,  russet,  gla- 
brous. Calyx  lobes  regularly  deciduous  in  all  fruits;  800  apples  picked 
and  examined  especially  with  reference  to  this  character,  had  all  lost 
the  lobes,  leaving  russet  scars  such  as  are  characteristic  of  fruit  with 
deciduous  calyx.  From  examination  of  the  description  sheets  of  fruits 
resulting  from  crosses  made,  it  is  found  that  of  212  fruits,  210  had 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  525 

lost  the  calyx  in  the  normal  way,  in  one  the  lobes  were  persistent,  and 
in  the  remaining  fruit  two  lobes  with  fleshy  bases  persisted,  while  the 
other  three  lobes  were  deciduous  in  the  regular  way.  Basin  medium  in 
depth,  broad,  acute,  regular.  Core  small,  elliptical,  median,  closed; 
core  lines  meeting,  cells  axile.  Carpels  elliptical,  entire,  glabrous,  mod- 


FIG.  61. — FRUITING  TWIG  OF  M.  microcarpa  (19644), 

NATURAL  SIZE 

From  a  dwarf  tree  grown  in  pot,  and  bearing  fruits  result- 
ing from  pollinations  made  March  3,  1914.  Photograph  taken 
July  30,  1914. 

erately  concave.  Seeds  plump,  dark  brown,  of  medium  size.  Flesh 
yellowish,  firm,  crisp,  juicy,  acid.  A  twig  on  dwarf  tree  grown  in  pot 
and  bearing  fruits  resulting  from  pollinations  made  March  3,  1914,  is 
shown  approximately  natural  size  in  Fig.  61,  from  photograph  taken 
July  30,  1914.  The  same  tree  again  bearing  fruit  in  1916  is  shown 


526 


BULLETIN  No.  275 


[June, 


FIG.    62. — DWARF    THEE  OF 
M.  microcarpa  (19644) 

IN  POT 

This  tree,  shown  bearing 
fruit  in  1916,  is  the  same  one 
from  which  the  twig  shown 
in  Fig.  61  was  taken. 


entire  in  Fig.  62,  from  photograph  taken 
June  21.  A  single  fruit  also  appears  at  the 
center  below  in  Fig.  54. 

The  affinities  of  this  species  are  with 
M.  baccata  and  it  is  doubtless  a  hybrid 
form  of  that  species. 

28.  Mains  niedwietzkyana  Dieck. 

Malus  medwietzkayana  Dieck.    Neuheiten 

Offerte  des  Nat.  arb.  Zoschen,  16.  1891. 

Wiener.  Illus.  Gartenz,  164.   1891. 

Card.  Chron.  5,  3d.  ser.   9,  461.    1891. 
Malus  niedwetzkayana  Dieck.     Neuheiten 

Offerte  des  Nat.  arb.  Zoschen,  18.  1892. 

Koehne.  Deut.  Dendrol.,  259.    1893. 
Pyrus   niedwetzkayana    Hemsley.    Curtis's 

Bot.  Mag.  3d  ser.  60,  plate  7975.  1904. 
Pyrus   malus   Durand   and   Jackson.     Ind. 

Kew.  Sup.  1,  262.    1906. 

This  curious  species  is  so  different  from 
any  other  form  of  Malus  that  it  is,  per- 
haps, worthy  of  consideration  in  some 
detail.  The  history  and  geographical  dis- 
tribution is  best  given  by  direct  quotation 
from  published  accounts  of  the  species. 
Dr.  Dieck,  who  named  the  species,  is  pro- 
prietor of  the  National  Arboretum  at 
Zoschen,  Saxony.  Shortly  after  the  ap- 
pearance of  his  catalog  of  novelties  which 
included  this  newly  constituted  species, 
Dr.  E.  Goeze  gave  the  following  account 
of  the  species.1 


"M.  medwietzkyana — This  curious  wilding 
has,  as  a  wild  or  a  cultivated  plant,  a  wide  dis- 
tribution in  West  and  Central  Asia,  and  has 
apparently  not  yet  been  described.  Dr.  Dieck  obtained  it  from  Kashgar  and  the 
Talgar  plateau  in  South-west  Siberia,  but  it  is  probable  that  under  the  name  of 
Kuzugjoran  an  identical  form  exists  in  the  lesser  Caucasus,  and  which  is  highly 
esteemed  by  the  Swabian  colonists  in  Trans-Caucasia.  Except  the  old  leaves,  all 
parts  of  the  tree  are  red,  bark  and  wood,  as  well  as  flowers  and  fruits,  which 
resemble  small  Sina-apples;  even  the  pulp,  which  has  a  fine  flavour,  is  of  a  dark 
rosy  colour.  In  Kashgar  the  cultivated  form  bears  the  name,  Kisil  alma;  the 
wild  variety  is  to  be  named  after  President  Medwietzky,  who  collected  it  with 
many  other  interesting  shrubs  in  South-west  Siberia." 


'Goeze,  E.  Gard.  Chron.  9,  461.    1891. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  527 

Following  is  the  account  of  the  species  as  given  by  W.  B.  Hems- 
ley,  Keeper  of  the  Herbarium  and  Library,  Royal  Gardens,  Kew.1 

"This  remarkably  distinct  apple  is  an  instance  in  which  it  seems  better  for 
practical  purposes  to  avoid  the  theoretical  species  and  publish  it  under  the  single 
name  it  goes  by  in  cultivation.  It  might  be  argued  that  it  is  only  a  variety  of 
Pyrus  Malus  L.,  but  we  do  not  propose  discussing  that  question  here.  It  certainly 
is  a  most  striking  object,  whether  in  flower  or  in  fruit. 

"As  to  the  spelling  of  the  distinctive  name,  we  have  adopted  the  one  used 
by  the  author  in  his  second  account  of  the  plant,  where,  however,  he  gives  no 
explanation  of  the  deviation  from  the  first.  In  each  case  he  states  that  he  names 
it  after  his  patron,  who  collected  it  wild  in  the  Hi  District,  South-west  Siberia. 
Mr.  Dieck  further  states  that  this  apple  is  widely  spread  in  Western  and  Central 
Asia,  both  in  a  wild  state  and  cultivated  and  he  believes  it  is  the  same  as  a  com- 
mon wild  apple  of  the  Caucasus,  which  is  highly  prized  for  its  fruit  by  the  Swa- 
bian  colonists.  He  received  it  from  Kashgar  and  the  Plateau  of  Talgar  and  the 
European  stock  appears  to  have  been  raised  from  the  seed  of  cultivated  trees 
in  the  former  locality,  where  it  is  called  'Kisil  alma'  or  red  apple.  With  the 
exception  of  the  leaves  all  parts  of  this  apple  are  red, — bark,  wood,  flowers  and 
fruit  and  the  leaves  turn  red  in  autumn.  Even  the  flesh  of  the  nice-tasting  fruit 
is  of  a  deep  rose-red. 

"Pyrus  Niedzwetzkayana  is  hardy  at  Kew  where  it  flowered  profusely  last 
spring  and  is  just  ripening  fruit  at  the  time  of  writing  this  (Sept.  1,  1904).  The 
fruit  actually  represented  in  the  plate  is  from  a  drawing  made  by  Mr.  George 
Massee,  of  a  very  fine  fruiting  specimen  sent  to  Kew  from  Bitton,  in  August, 
1901,  by  Canon  Ellacombe." 

Continuing,  Mr.  Hemsley  gives  the  following  description  of  the 
plant: 

"A  small  free-growing  tree.  Flowering-branches  long,  straight,  stiff,  rather 
thick:  bark  smooth,  very  dark  purple.  Leaves  on  long  slender  petioles,  on  the 
fruiting  branches  rather  thick,  stiff,  nearly  glabrous,  tinged  red,  lanceolate,  ob- 
lanceolate  or  oblong,  three  to  five  inches  long  without  the  petiole,  finely  crenately- 
toothed,  shortly  acuminate,  slightly  hairy  along  the  midrib;  petiole  one  to  two 
inches  long,  bright  red  as  well  as  the  midrib,  slightly  hairy.  Flowers  deep  rose- 
purple,  an  inch  and  a  half  to  an  inch  and  three-quarters  across,  very  numerous, 
clustered  at  the  ends  of  very  short  lateral  branchlets;  stalks  slender,  six  to  nine 
inches  long.  Calyx  woolly,  white;  lobes  lanceolate,  acute,  about  a  quarter  of  an 
inch  long.  Petals  obovate.  Stamens  longer  than  the  smooth  styles.  Fruit,  pendu- 
lous, conical,  one  inch  and  three-quarters  to  two  inches  long,  skin  crimson-purple, 
flesh  rose-purple  throughout." — W.  B.  H. 

The  plate  accompanying  Mr.  Hemsley's  article  shows  a  flowering 
branch  with  numerous  flowers  which  appear  lighter  in  color  than  those 
produced  by  trees  in  the  Station  collection.  The  fruit,  said  to  be  nat- 
ural in  size,  measures  5  cm.  in  long  diameter  and  4.8  cm.  in  transverse 
diameter.  It  shows  a  markedly  conical  apex  and  appears  to  be  ribbed. 

Scions  of  Malus  niedurietzkyana  were  received  from  the  Arnold 
Arboretum  thru  the  U.  S.  Department  of  Agriculture  January  29,  1907, 


'Hemsley,  W.  B.  Curtis's  Bot.  Mag.  3d.  ser.  60,  colored  plate  No.  7975.  1904. 


528  BULLETIN  No.  275  [June, 

as  number  19683.  Both  root-  and  top-grafts  were  made  and  most 
scions  started  growth,  but  all  died  before  the  end  of  the  season.  The 
second  lot  of  scions  direct  from  the  Arnold  Arboretum  January  9, 
1908,  were  added  to  the  collection  under  the  number  834.  At  present 
the  species  is  represented  by  one  tree,  top-worked  on  Fameuse  in 
1908,  which  flowered  for  the  first  time  in  1916;  five  trees  propagated 
in  1912,  and  one  tree  on  paradise  stock  in  pot,  grafted  February  24, 
1911,  and  forced  each  spring  since.  This  has  flowered  regularly  since 
1914.  From  the  experience  in  propagating  this  species  it  may  be  said 
that  in  nearly  all  cases  the  initial  growth  from  the  graft  has  been  slow, 
feeble,  and  disappointing,  but  each  succeeding  year  there  has  been  a 
decided  increase  in  vigor  of  growth.  All  trees  are  spreading  in  habit 
and  there  is  some  tendency  to  the  production  of  long  straggling 
branches  that  need  to  be  controlled  in  order  to  preserve  symmetry. 
Bark  of  trunk  and  main  branches  is  very  dark  brownish-black  with  a 
tinge  of  purplish-red,  twigs  have  much  the  same  colors,  but  in  some- 
what lighter  shades.  Lenticels  are  numerous,  small,  transverse,  con- 
spicuous. 

Leaves. — Mostly  oblong  or  lanceolate,  but  some  are  ovate  or  even 
orbicular,  2%  to  4  inches  long  including  the  petiole,  which  is  usually 
about  1  inch  in  length,  acuminate,  crenate-dentate,  pubescent  below 
and  with  scattering  hairs  above  when  young,  becoming  glabrous  above 
and  nearly  but  not  entirely  so  below;  petioles  are  also  pubescent 
when  young,  but  become  entirely  glabrous  and  assume  a  bright  red 
color  which  extends  thru  the  midrib  and  larger  veins.  The  leaves  are 
rather  thin,  but  of  leathery  texture  even  when  young,  becoming  stiff 
in  autumn,  dark  green  with  a  red  or  purple  tinge  that  becomes  more 
pronounced  as  the  season  advances;  in  autumn  most  leaves  become 
entirely  red  or  purplish-red.  Stipules  minute,  linear,  falling  as  the 
leaves  expand. 

Flowers. — The  full  bloom  dates  vary  from  April  20  in  1921 
to  May  10  in  1920.  The  mean  date,  as  an  average  for  seven  years, 
is  about  May  2.  The  trees  flower  heavily  every  second  season  and 
seldom  fail  to  have  a  few  clusters.  Flowering  from  terminal  buds  of 
shoots  of  preceding  year  and  from  sessile  lateral  buds  at  various  points 
along  the  shoots,  but  principally  near  the  apex.  Of  68  clusters  recorded 
as  to  number  of  buds,  1  had  2,  10  had  4  each,  38  had  5  each,  18  had 
6  each,  and  1  had  7.  Buds  are  large,  globular,  becoming  elongated  as 
the  petals  increase  in  size;  the  color  is  a  deep  maroon  which  fades  to 
aster-purple  when  petals  are  about  ready  to  open.  Flowers  measured 
expand  from  4  to  5  cm.  Pedicels  short,  10  to  12  mm.  long,  stout,  pubes- 
cent, red,  as  is  also  the  heavily  pubescent  ovary.  Calyx  lobes  5, 
broadly  triangular,  4  to  5  mm.  long,  3  mm.  wide  at  base,  obtuse  or 
acute,  pubescent  both  sides  and  red  in  color.  Petals  5,  reddish  aster- 
purple,  both  inside  and  outside,  oval,  rounded  at  apex,  abruptly  taper- 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


529 


ing  to  the  claw  which  in  fully  open  flowers  is  distinct,  wide,  and  rather 
long.  Stamens  vary  in  number  from  23  to  27,  filaments  8  mm.  long, 
rose-red,  shorter  than  the  styles;  anthers  plump,  yellow,  overspread 
with  purple,  darker  in  color  than  the  filaments,  pollen  abundant,  sep- 
arating readily  on  dehiscence  and  not  inclined  to  adhere  in  masses. 
Styles  5,  slender,  12  mm.  long,  equal,  rose-red,  connate  less  than  one- 
fourth  the  length,  hairy  from  base  to  above  point  of  separation. 


FIG.  63. — BUD  CLUSTER  OF  M.  niedwietzkyana  DIECK  (834), 

PHOTOGRAPHED  MARCH  21,  1914 

The  buds  are  a  deep  maroon  which  fades  to  an  aster-purple  when 
the  petals  are  about  ready  to  open.  The  trees  of  this  species  flower 
heavily  every  other. season,  and  seldom  fail  to  have  a  few  clusters. 

Stigmas  yellow,  oval  or  somewhat  irregular,  oblique,  slightly  prolonged 
down  the  styles.  A  flower  cluster  with  one  expanded  flower  is  shown 
in  Fig.  63. 

Fruit. — Roundish-oblate  with  conical,  somewhat  irregular  apex. 
The  fruit  described  weighed  23.8  grams,  measured  36  mm.  in  vertical 
diameter  and  38  mm.  in  transverse  diameter,  and  possibly  had  not 
reached  full  maturity  when  it  fell  from  the  tree.  Ground  color  green 
almost  completely  obscured  by  the  crimson-purple  over-color;  the 
dark  purplish  color  is  accentuated  by  the  presence  of  an  abundant, 
powdery,  purple  bloom;  skin  smooth,  thin,  tough;  dots  few,  large, 
irregular,  areolar,  conspicuous.  Cavity  medium  in  depth,  rather  broad, 
acuminate,  regular;  stem  short,  stout,  clavate,  erect,  green,  pubescent; 
calyx  of  medium  size,  closed.  Basin  moderately  deep,  medium  in 
breadth,  acute,  irregular,  ribbed;  calyx  lobes  of  medium  size,  broad 
and  short,  obtuse;  tips  reflexed,  bases  somewhat  separated.  Carpels 


530 


BULLETIN  No.  275 


[June, 


elliptical,  entire,  tufted,  moderately  concave.  Flesh  tinged  thruout 
with  reddish-pink,  firm,  somewhat  dry, 'subacid,  and  with  a  slightly 
bitter  taste.  As  grown  at  this  Station,  the  niedwietzkyana  fruit  does 
not  have  the  fineness  and  niceness  of  quality  which  it  is  described  as 
having  in  the  Siberian  Plateau,  but  is  rather  poor,  having  a  flat  taste, 
and  lack  of  flavor.  The  fruit  described  (Fig.  64)  developed  from  a 
flower  hand  pollinated  with  Yellow  Transparent  pollen  March  7,  1916. 
It  fell  from  the  tree  June  16  and  was  described  the  same  day. 

M.  niedwietzkyana  has  been  used  quite  freely  in  crosses  altho 
the  degree  of  success  attained  has  been  very  low.    As  the  female 


FIG.  64. — FRUIT  OF  M.  niedwietzkyana  DIECK  (834)  FROM  FLOWER 
POLLINATED  IN  GREENHOUSE  BY  YELLOW  TRANSPARENT, 

MARCH  7.   PHOTOGRAPHED  JUNE  7,  1916 

The  fruit  of  this  species  grown  at  this  Station  is  not  of  such  fine 
quality  as  it  is  said  to  have  in  the  Siberian  Plateau.  It  is  character- 
ized by  a  flat  taste  and  lack  of  flavor. 


parent  it  has  served  in  19  crosses  with  pollen  from  11  orchard  varieties; 
14  of  these  failed;  5,  2  by  Domine,  2  by  Delicious,  and  1  by  Yellow 
Transparent,  matured  8  fruits.  Pollinations  were  10%  percent  success- 
ful for  these  5,  but  less  than  2  percent  successful  for  the  whole  group 
of  crosses.  In  orchard  there  are  28  seedlings  derived  from  these  5 
crosses.  Pollen  of  niedwietzkyana  has  been  used  in  34  crosses  on  17 
orchard  varieties  and  11  crab-forms;  18  of  the  crosses  failed  and  from 
16  crosses  there  are  living  in  orchard  253  trees  at  ages  of  6  to  8  years. 
For  the  whole  group  580  pollinations  matured  87  fruits,  or  15  percent 
of  the  pollinations  were  successful. 


19261 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


531 


29.  Mains  prunijolia  macrocarpa  (837) 

This  is  represented  in  the  collection  under  the  number  837  by  one 
tree  from  root-graft  made  January  18,  1908;  one  tree  from  top-graft 
on  paradise  stock  in  pot,  made  February  12,  1910;  one  top-graft  on 
Fameuse  April  6,  1908;  and  several  younger  trees  propagated  in  later 
years. 

The  tree  from  root-graft  of  1908  best  exhibits  the  characteristics 
of  this  form.    It  is  of  very  erect  habit,  15  feet  in  height  with  an 
extreme  spread  of  11  feet  5  inches, 
and  a  trunk  diameter  of  5.4  inches. 
Bark  light  brown  with  a  tinge  of 
olive-green;     twigs     are     reddish- 
brown,  glabrous  except  when  very 
young,    and    then    only    sparsely 
pubescent. 

Leaves. — Ovate  or  oblong,  or 
some  of  the  smaller  lanceolate,  2% 
to  5  inches  long,  %  inch  to  2  inches 
wide,  acuminate,  crenate-dentate, 
or  in  some  cases  serrate  towards  the 
apex,  sparingly  pubescent  below 
when  young,  becoming  glabrous, 
thick,  leathery  in  texture.  Petioles 
stout,  %  to  V/2  inches  long,  glab- 
rous. 

Flowers. — Produced  from  termi- 
nal and  lateral  buds  of  terminal 
shoots  and  from  terminal  buds  of 
spurs.  Buds  small,  globular,  pink, 
fading  to  pure  white  as  flowers 
open.  Flower  expands  1%  inches. 
Pedicels  slender,  25  mm.  long, 
sparsely  pubescent,  lower  part  of 
ovary  pubescent,  upper  part  and 
outer  surface  of  calyx  lobes  gla- 
brous. Calyx  lobes  5,  long  acumi- 
nate, pubescent  within;  petals  ob- 
ovate,  rounded  at  apex,  below 
tapering  gradually  to  the  short  but 
broad  claw.  Stamens  in  26  flowers  examined  vary  in  number  from  7 
to  18  with  an  average  less  than  15,  filaments  slender,  7  to  8  mm.  long, 
anthers  lemon-yellow,  not  well  filled ;  styles  slender,  4  to  7  in  number, 
of  equal  length,  8  to  9  mm.  long,  stigmas  small,  capitate.  A  twig  in 
flower  as  photographed  in  the  greenhouse  March  12,  1913,  is  shown 
as  Fig.  65. 


FIG.    65. — TWIG    OF    M.    prunijolia 

macrocarpa  (837)  IN  BUD  IN 

GREENHOUSE,  MARCH   12 


532  BULLETIN  No.  275  [June, 

Fruit. — Roundish-oblate,  base  regular,  apex  conical  and  some- 
what irregular;  ground  color  yellow  blushed  in  shades  of  red  from 
bright  crimson  to  very  dark  red;  skin  smooth,  thin,  tender;  dots  few, 
small,  inconspicuous;  cavity  shallow,  broad,  obtuse,  irregular;  stem 
25  to  35  mm.  long,  slender,  oblique,  glabrous;  basin  shallow,  broad, 
obtuse,  ridged;  calyx  small,  open.  Persistence  of  calyx  lobes  is  not  con- 
stant in  this  form;  of  20  fruits  examined  14  had  normally  persistent 
lobes  and  in  6  the  lobes  were  deciduous.  These  fruits  were  weighed 


FIG    66. — FRUITS   OF   M.  prunifolia   macrocarpa 

(837),  NATURAL  SIZE,  AUGUST  17 
This  fruit  is  yellow  in  color,  blushed  in  shades 
of  red  from  bright  crimson  to  very  dark  red. 

and  measured;  the  average  is  found  to  be  as  follows;  weight  6.72 
grams;  longitudinal  diameter  20  mm.;  transverse  diameter  25  mm.  In 
seed  production  the  fruits  were  much  above  the  average  for  the  crab 
group;  this  form  has  an  average  of  7  seeds  to  each  fruit.  Two  fruits 
of  No.  837  photographed  August  17,  1916,  at  full  maturity,  from  one  of 
the  top-grafted  trees  are  shown  in  Fig.  66.  This  form  of  M .  prunifolia 
has  been  used  as  female  in  eleven  crosses,  six  of  which  failed  in  fruit 
production,  in  one  seeds  did  not  germinate,  and  in  one  the  seedlings 
died  soon  after  appearance  above  ground.  Only  three  crosses  are  rep- 
resented by  progeny  in  orchard;  a  cross  by  M.  siberica  jrutico  coc- 
cinea  (19643)  by  twenty-six  trees,  eleven  years  old,  one  by  Olden- 
burg by  seven  trees  eight  years  old,  and  one  by  Jefferis  by  130  trees 
seven  years  old.  For  the  group  there  were  438  pollinations  yielding  62 
fruits  or  14.15  percent  of  the  pollinations  successful.  The  variety  has 
not  been  used  as  a  pollen  parent. 


1936} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


533 


30.  Mains  prunifolia  var.  (838) 

Represented  in  the  collection  by  six  trees  grown  from  root-grafts 
made  with  the  scions  received  from  the  Arnold  Arboretum  in  January, 


FIG.    67. — TREE    OF    M.    prunifolia    VAR.    (838)      PHOTO- 
GRAPHED OCTOBER  15.    FIG.  68. — SHOOT  IN  FLOWER 

PHOTOGRAPHED  APRIL  29 

The  tree  of  this  species  is  of  erect,  symmetrical  habit. 
Flowering  is  inclined  to  be  profuse,  the  flowers  on  some 
shoots  being  so  concentrated  that  the  leaves  are  entirely 
obscured.  The  twig  in  Fig.  68  was  photographed  after 
the  petals  had  partly  fallen. 

1908.    This  is  No.  838,  which  in  habit  of  growth  and  manner  of  flower- 
ing appears  much  as  does  No.  837  described  above. 

The  trees,  now  sixteen  years  old,  are  similar  and  of  erect  sym- 
metrical habit;  the  bark  of  trunk  and  branches  is  light  greenish-brown, 
that  of  twigs  bright  reddish-brown.  Flowering  twigs  are  glabrous,  but 
the  more  robust  non-flowering  shoots  are  covered  with  close  pubescence 


534  BULLETIN  No.  275  [June, 

which  is  retained  thru  the  season.  The  largest  tree  is  20  feet  high,  has 
an  extreme  spread  of  14  feet  8  inches,  and  a  trunk  diameter  of  6 
inches,  the  other  trees  are  but  slightly  under  these  dimensions.  Habit 
is  illustrated  in  Fig.  67  from  photograph  taken  October  15,  1913. 

Leaves. — Elliptical,  ovate  or  oblong,  3  to  4%  inches  long,  %  inch 
to  2  inches  wide,  acute,  or  acuminate,  serrate  or  coarsely  dentate,  gla- 
brous above  even  when  young.  The  lower  surface  of  young  leaves  is 
scantily  covered  with  a  short  pubescence,  in  age  some  leaves  lose  this 
pubescence  entirely,  others  retain  it,  or  at  least  part  of  it  until  they 
fall ;  texture  somewhat  thick  and  leathery. 

Flowers. — In  this  variety  the  flowers  develop  chiefly  from  lateral 
buds  occurring  along  terminal  shoots.  Commonly  all  buds  within  a 
zone  beginning  2  to  4  inches  from  the  apex  of  the  shoot  and  extending 
down  from  4  to  12  or  15  inches  contain  flower  clusters,  while  buds 
about  the  tip  and  below  the  zone  are  leaf  buds  only.  The  flowering 
thus  concentrated  on  numerous  erect  shoots  masses  the  color  and  adds 
to  the  beauty  of  the  tree  when  in  flower.  Flowers  are  also  produced 
from  terminal  buds  of  short  spurs  on  lower  branches,  but  these  are  so 
scattered  as  to  attract  no  attention.  Some  clusters  have  4  or  5  flowers, 
but  most  of  them  have  6.  Pedicels  32  to  44  mm.  long,  slender,  sparsely 
pubescent.  Leaves  are  somewhat  in  advance  of  flowers  but  the  long 
pedicels  bring  the  flowers  out  so  that  when  open  they  are  fully  exposed. 
Shoots  in  flower  often  appear  as  in  Fig.  68,  where  flowers  are  in  con- 
trast with  the  light  green  leaves,  but  on  some  shoots  the  flowers  are  so 
concentrated  that  the  leaves  are  entirely  obscured.  The  figure  given 
is  from  a  photograph  taken  April  29,  1915,  after  petals  had  partly 
fallen.  Buds  globular,  light  pink,  becoming  ovate  in  form  and  fading 
to  nearly  white.  As  the  bud  cluster  opens  the  axis  elongates  somewhat 
and  there  is  some  vertical  separation  of  the  points  of  attachment  of 
pedicels,  an  arrangement  that  suggests  the  raceme,  rather  than  the 
umbel  or  cyme.  Ovary  glabrous,  calyx  lobes  5,  linear,  acute,  7  mm. 
long,  2  mm.  wide  at  base,  pubescent  on  the  inner  surface,  glabrous  on 
the  outer,  frequently  more  or  less  tinged  with  red.  Petals  5,  oval  in 
form,  20  mm.  long,  12  mm.  wide,  rounded  at  apex  and  tapering 
abruptly  to  the  short  claw,  mostly  pure  white,  occasionally  with  a 
pink  or  pale  rose-purple  tinge.  Stamens  in  33  buds  examined  range 
in  number  from  16  to  24  with  an  average  of  20,  filaments  slender  5 
to  7  mm.  long;  anthers  plump,  light  yellow.  Styles  5,  slender,  11  mm. 
long,  longer  than  the  stamens,  connate  3  mm.  from  base,  glabrous  at 
base  for  1.5  mm.,  hairy  1.5  mm.  in  either  direction  from  the  point  of 
separation;  stigmas  elongated,  oblique,  irregular  in  form. 

Fruit. — Round  or  slightly  oblate,  somewhat  conical,  varying 
greatly  in  size  on  the  same  plant.  The  extremes  in  weight  for  350 
fruits  are  2.15  grams  and  8.06  grams,  the  average  is  6.55  grams.  From 
these  fruits  the  average  diameters  are  found  to  be  20  mm.  longitudinal 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


535 


and  23  mm.  tranverse.  Base  regular,  ribbed,  sides  equal;  color  a  clear 
yellow;  occasionally  fruits  are  found  having  a  bronze  blush  over 
restricted  areas  and  rarely  this  blushed  area  becomes  pink.  Bloom 
moderately  abundant,  powdery,  gray,  skin  smooth,  thin,  tender,  dots 
few,  of  medium  size,  areolar  with  russet  center,  inconspicuous.  Cavity 
medium  in  depth,  narrow,  acuminate,  regular;  stem  long,  32  to  44  mm., 


FIG.  69. — CLUSTER  OF  FRUIT  OF  M.  prunifolia  VAR.  (838), 
SEPTEMBER  16 


green,  or  late  in  the  fall  becoming  red,  glabrous.  Calyx  large,  pubes- 
cent, closed;  basin  shallow  and  narrow  or  often  none,  usually  ribbed 
about  the  bases  of  the  long  slender,  acute  reflexed,  commonly  persist- 
ent calyx  lobes.  In  this  matter  of  calyx  lobes  there  is  not  perfect 
constancy.  In  1915,  of  2,239  fruits  examined  with  special  reference  to 


536 


BULLETIN  No.  275 


[June, 


this  character  2,114  or  94.41  percent  had  persistent  lobes  and  125  or 
5.59  percent  had  deciduous  lobes;  in  1916  the  examination  included 
2,316  fruits,  in  all  but  4  of  which  the  lobes  were  persistent,  that  is  to 
say  99.82  percent  were  persistent  and  0.18  percent  deciduous.  Consid- 
ering the  total  4,559  fruits  in  the  two  seasons,  4,430  or  97.17  percent 
retained  the  calyx  lobes,  while  for  129  fruits  or  2.83  percent  the  lobes 
were  regularly  deciduous.  Core  large,  oblate,  median,  open;  carpels 
roundish,  emarginate,  tufted,  deeply  concave.  Flesh  yellowish,  tender, 


FIG.  70. — FRUITS  OF  FOUR  OF  THE  CRAB  FORMS  OF  MALUS 
Left  to  right:  M.  baccata  (red  fruit)  (806),  M.  baccata  (red  fruit,  late)  (807), 
M.  baccata  maxima  (810),  M.  prunifolia  var.  (838). 


crisp,  moderately  juicy,  acid.  A  cluster  of  fruits  from  terminal  bud  of 
a  short  spur  is  shown  in  Fig.  69  from  a  photograph  made  September 
16,  1915.  A  single  fruit  is  to  be  seen  at  the  extreme  right  in  Fig.  70,  in 
contrast  with  three  forms  of  M.  baccata. 

This  form  of  M .  prunifolia  has  been  used  as  female  in  22  crosses 
with  pollen  from  15  varieties  and  3  crab  forms  and  only  one, 
an  attempted  cross  by  Stayman  Winesap,  failed  in  maturing  fruit; 
two  other  crosses,  one  by  M.  toringo,  and  one  by  Arkansas,  passed 
out  because  of  low  vitality  of  seedlings.  There  are  19  crosses  repre- 
sented by  817  seedlings  in  orchard  at  ages  from  7  to  13  years.  The 
aggregate  of  pollinations  is  1,089;  they  matured  651  fruits  or  were 
59.77  percent  successful.  This  is  a  high  degree  of  success  and  ranks 
the  female  parent  as  one  of  the  best  breeders  in  the  collection. 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  537 

This  same  form  has  been  used  as  the  pollen  parent  in  19  crosses 
on  15  varieties  and  one  crab.  Five  attempts  failed  and  14  crosses 
are  represented  in  orchard  by  948  seedlings  now  7  to  13  years  of  age. 
It  is  a  coincidence  that  the  number  of  pollinations  is  the  same  as  in 
the  group  where  this  crab  was  used  as  female,  1,089;  the  number  of 
fruits  matured  is  287,  giving  26.35  as  the  percentage  of  successful  pol- 
linations. This  is  a  good  percentage  altho  less  than  half  that  attained 
when  the  plant  served  as  female  parent. 

31.  Mains  prunifolia  xanthocarpa   (839) 

Rather  indifferent  success  has  attended  the  propagation  and  main- 
tenance of  this  number  in  the  Station  collection.  Ten  root-grafts 
made  with  the  scions  received  in  January,  1908,  all  failed.  On 
April  7,  1908,  two  scions,  reserved  for  the  purpose,  were  top-worked  on 
a  Virginia  Crab  seedling ;  these  lived  and  grew,  but  the  union  obtained 
was  less  perfect  than  with  most  other  forms  grafted  at  the  same  time. 
Scions  from  the  grafts  of  1908  were  worked  on  the  lower  branches  of 
the  stock  March  11,  1911,  and  on  October  25  the  tree  appeared  as  in 
Fig.  71,  from  photograph  taken  on  that  date.  In  February,  1913,  this 
tree  was  shifted  with  others  to  another  tract:  in  1914  the  trunk  was 
attacked  by  blight  and  the  tree  died. 

Scions  from  the  top-graft  were  grafted  on  a  potted  paradise  stock 
February  21,  1910.  This  tree  has  been  forced  each  season  since:  it 
flowered  and  fruited  in  1914  and  again  in  1916,  and  the  flowers  and 
fruits  from  the  greenhouse  are  the  only  ones  thus  far  produced  by  this 
variety  of  Malus.  With  scions  from  the  same  source  root-grafts  were 
made  in  February,  1912,  they  were  planted  out  in  the  spring  and 
some  made  a  feeble  growth,  but  all  were  dead  in  the  fall.  Other  scions 
were  top-worked  on  a  Grimes  stock  April  4,  1912.  These  scions  grew 
feebly  for  two  seasons  and  died  in  1914.  Thus  the  only  representative 
of  No.  839  is  the  dwarf  tree  on  paradise  stock.  So  far  as  can  be 
judged  from  the  growth  made  by  top-grafts  the  tree  habit  is  upright 
and  in  every  way  similar  to  Nos.  837  and  838. 

Leaves. — Ovate  or  some  of  the  smaller  elliptical,  2  to  4%  inches 
long,  1  to  2%  inches  wide,  acuminate,  crenate  or  dentate,  glabrous 
both  sides;  petioles  rather  short,  stout,  glabrous,  at  least  when  mature; 
stipules  lanceolate,  petioled,  mostly  persisting. 

Flowers. — Those  produced  in  the  greenhouse  in  1914  were  from 
terminal  buds  of  shoots  or  short  spurs.  Pedicels  slender,  15  to  17  mm. 
long,  slightly  pubescent,  light  green.  Calyx  lobes  5,  acuminate,  7  mm. 
long  and  1.5  mm.  wide  at  base,  separated  somewhat  at  base,  glabrous 
outside,  heavily  pubescent  within.  Petals  5,  light  pink  in  bud,  fading 
to  white  in  open  flowers,  oval,  11  mm.  long  and  8  mm.  wide  with  very 
short  claw.  Flower  expands  26  mm.  Stamens  vary  in  number  from  15 


638 


BULLETIN  No.  275 


[June, 


to  21,  but  a  large  majority  of  the  flowers  examined  have  the  normal 
number  20;  filaments  slender,  5  to  6  mm.  long,  anthers  plump,  light 
yellow.  Styles  unequal  in  length,  5  to  9  mm.  long;  in  58  flowers  exam- 
ined 50  had  5  each,  6  had  4  each, 
1  had  2,  and  1  had  1;  erect,  gla- 
brous; stigmas  oval,  oblique. 

Fruit. — Small,  oblong,  irregular 
at  base,  truncate  and  irregular  at 
apex,  sides  unequal,  ground  color  yel- 
low, blushed  with  an  over-color  of 
light  red  which  in  some  fruits  deepens 
almost  to  dark  red.  Skin  smooth, 
thin,  tough,  dots  few,  small,  regular, 
round,  white,  inconspicuous;  cav- 
ity moderately  deep,  medium  in 
width,  acute,  irregular.  Stem  slen- 
der, 24  mm.  long,  erect,  green,  pu- 
bescent; the  average  weight  of  3 
fruits  is  1.1  grams;  average  longi- 
tudinal diameter  12  mm.,  transverse 
diameter  11  mm.;  calyx  lobes  de- 
ciduous in  all  fruits;  core  large, 
elliptical,  sessile,  closed.  Cells  axile, 
variable  in  form;  carpels  elliptical, 
emarginate,  glabrous,  moderately 
concave.  Flesh  yellowish,  tender, 
moderately  juicy,  subacid.  Used  as 
female  in  six  crosses,  four  of  which 
failed.  A  cross  of  Domine  in  1914 
from  47  pollinations  matured  4 
fruits;  only  1  of  3  seeds  germinated 
and  this  seedling  now  in  its  tenth 
year  grades  as  "good,"  is  12  feet  7 
inches  high,  has  spread  of  7  feet  1 
inch  and  a  diameter  of  3.3  inches. 
One  other  cross  by  M.  prunifolia 
var.  (19651)  from  49  pollinations 
matured  22  fruits  with  25  seeds, 
only  1  of  which  germinated;  this 
seedling  now  in  its  seventh  year  is 
graded  as  "good,"  has  a  height  of 

5  feet  4  inches,  a  spread  of  4  feet  7  inches,  and  is  1.2  inches  in  diam- 
eter. Thus  the  group  with  158  pollinations  was  approximately  19 
percent  successful  in  fruit  production,  but  is  represented  in  orchard  by 
only  two  seedlings.  As  a  pollen  parent  this  form  of  Mains  was  used  in 


FIG.   71. — TOP-WORKED  TREE  OF   M. 

prunifolia  xanthocarpa  (839) 
The  propagation  and  maintenance 
of  this  species  have  not  been  very 
successful  at  this  Station.  The  tree 
illustrated  here  was  top-worked  April 
7  and  March  11,  and  was  photo- 
graphed October  25  of  the  same  year. 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  539 

thirteen  crosses,  nine  of  which  failed;  the  four  crosses  maturing  fruits 
are  represented  in  orchard  by  nineteen  trees.  For  the  group  the  162 
pollinations  were  11.72  percent  successful. 

32.  Mains  prunifolia  var.   (856) 

The  scions  for  this  number  in  the  Station  collection  came  from 
the  Arnold  Arboretum  in  January,  1908,  and  were  labelled  "Mams  sp? 
No.  5004."  The  tree  from  which  the  scions  came  is  one  of  several 
seedlings  grown  from  seeds  collected  by  Dr.  C.  S.  Sargent  in  Japan  in 
1892;  it  has  not  attained  large  size  and  exhibits  the  characteristics  of 
the  prunifolia  group.  This  variety  is  represented  in  the  Station 
collection  by  one  tree  now  in  its  seventeenth  year  from  root-graft 
made  January  11,  1908,  and  two  trees,  also  in  the  seventeenth  year, 
top-worked  on  Virginia  Crab  seedlings  April  9,  1908.  The  top-grafts 
of  1908  began  flowering  in  1911  and  have  bloomed  abundantly  each 
year  since.  Fig.  72  from  a  photograph  of  one  of  these  trees  taken  May 
9,  1916,  shows  fairly  well  the  possibilities  of  this  variety  as  an  orna- 
mental. The  tree  root-grafted  in  1908  did  not  flower  until  1914  and 
not  until  1916  was  the  bloom  abundant.  This  tree  now  has  dimen- 
sions as  follows;  height  15  feet  7  inches;  spread  18  feet  5  inches, 
trunk  diameter  7.2  inches.  All  trees  are  vigorous,  of  erect  habit  at 
first,  becoming  spreading.  Foliage  very  dense.  The  bark  of  trunk  and 
larger  branches  is  dark  olive-green,  twigs  reddish-brown,  glabrous. 

Leaves. — Large,  3  to  6  inches  in  length,  1  to  2%  inches  wide,  oval, 
or  elliptical,  tapering  equally  above  and  below,  acuminate,  crenate  or 
bluntly  serrate,  slightly  pubescent  on  both  sides  when  young,  becoming 
glabrous  thruout;  petioles  slender,  %  inch  to  2  inches  long,  glabrous  at 
maturity. 

Flowers. — Produced  from  terminal  and  lateral  buds  of  shoots  of 
the  preceding  year  and  to  some  extent  from  terminal  buds  of  short 
spurs  from  older  wood.  In  numbers  of  buds  to  the  cluster  there  is 
about  equal  division  between  clusters  having  5  buds  and  those  having 
6.  Young  buds  are  globular,  exceeded  in  length  by  the  connivent  tips 
of  the  calyx  lobes ;  in  development  they  elongate,  equalling  or  slightly 
exceeding  the  calyx  lobes,  light  pink  fading  to  white.  The  slender, 
scantily  pubescent  pedicels  elongate  as  the  buds  enlarge,  becoming  30 
mm.  to  35  mm.  in  length  before  the  flowers  open;  this  length  is  suffi- 
cient to  extend  the  buds  beyond  the  leaves  so  that  they  are  conspicu- 
ous; ovaries  covered  with  a  dense  close  pubescence;  calyx  lobes  linear, 
acuminate,  9  mm.  long,  2  mm.  wide,  glabrous  without,  margin  and 
inner  surface  pubescent. 

Flower  expands  30  mm.  to  35  mm.;  petals  oval  or  obovate, 
rounded  at  apex,  tapering  at  base  to  a  short  but  distinct  claw,  14  mm. 
to  17  mm.  long,  8  mm.  to  10  mm.  wide,  pure  white.  Stamens  20,  fila- 


540 


BULLETIN  No.  275 


[June. 


merits  slender,  8  mm.  to  10  mm.  long,  anthers  plump,  light  yellow. 
Styles  5,  slender,  11  mm.  long,  connate  4  mm.  up  from  base,  glabrous 
at  base,  but  slightly  hairy  beginning  1  mm.  from  base  and  extending 
up  5  mm.  to  6  mm.,  stigmas  small,  oval,  oblique. 


FIG.  72. — TOP-WORKED  TREE  OF  M.  prunifolia 

var.  (856)  IN  BLOOM 

The  tree  illustrated  here  is  a  top-graft  of  1908,  which  began 
flowering  in  1911  and  has  bloomed  abundantly  each  year  since. 
The  photograph,  which  was  made  May  9,  1916,  shows  the  possi- 
bilities of  this  variety  as  an  ornamental. 


Fruit. — Small,  individual  weight  as  averaged  from  100  fruits  is 
2.18  grams;  uniform  in  size,  vertical  diameter  14  mm.,  transverse 
diameter  15  mm.;  pedicels  slender,  erect,  35  mm.  long,  glabrous.  Most 
fruits  are  uniformly  yellow,  occasionally  a  small  area  exhibits  a  bronze 
blush.  Cavity  medium  in  depth,  broad,  angular;  basin  shallow,  broad, 
often  prominently  ribbed;  calyx  lobes  in  part  persistent  and  in  part 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  541 

deciduous;  of  5,270  fruits  examined  in  regard  to  this  character  3,048, 
or  57.83  percent,  had  persistent  lobes  and  2,222,  or  42.17  percent,  had 
deciduous  lobes. 

Core  medium  in  size,  nearly  globular,  nearly  sessile,  closed;  cells 
axile,  uniform;  carpels  ovate,  emarginate,  seeds  plump,  rather  small, 
light  brown.  Flesh  yellowish,  firm,  juicy,  subacid.  As  to  number  of 
cells  the  100  fruits  examined  divide  as  follows.  Seven  had  3  cells  each, 
49  had  4  each,  and  44  had  each  the  normal  5  cells.  The  number  of 
plump,  apparently  good  seeds  is  497,  an  average  of  4.97  to  each  fruit; 
this  gives  this  form  of  malus  an  intermediate  position  in  seed  produc- 


FIG.  73. — FRUITS  OF  FIVE  OF  THE  CRAB  FORMS  OF  MALUS,  NATURAL  SIZE 
Left  to  right:    M.  siberica  frutico  coccinea  (19643),  M.  scheideckeri  (19646). 
M.  spectabUis  (848),  M.  ringo  (840),  M.  prunifolia  var.  (856). 


tion,  for  of  25  crab-like  forms  for  which  record  has  been  made  the 
average  seed  production  is  4.22  seeds  to  each  fruit;  13  forms  have 
averages  less  than  for  M.  prunifolia  (856)  and  11  forms  have  higher 
averages.  The  maximum  of  7.80  is  attained  by  M.  malus  ft.  pi.  (833) 
and  the  minimum  of  1.32  falls  to  M.  jusca  (841).  A  single  fruit  of 
M.  prunifolia  (856)  is  shown  in  Fig.  73. 

33.  Malus  prunifolia  var.  (19651) 

Scions  from  which  trees  of  this  variety  of  Malus  were  grown  were 
included  in  the  lot  received  in  January,  1907,  from  the  Arnold  Arbor- 
etum thru  the  U.  S.  Department  of  Agriculture.  They  bore  the  num- 
ber 19651  and  were  labelled  M.  arnoldiana.  Long  before  the  trees 
produced  flowers  and  fruits  it  was  observed  that  they  were  different 


542 


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[June, 


from  those  labelled  M.  arnoldiana  under  the  number  802.  When 
fruiting  began  it  was  definitely  determined  that  No.  19651  repre- 
sents a  form  of  M.  prunifolia  and  that  it  is  distinct  from  any  other 
form  in  the  collection.  This  variety  of  M.  prunifolia  is  represented 
in  the  collection  by  one  tree  from  root-graft  of  January,  1907,  and  one 


FIG.  74. — TREE  OF  M.  prunifolia  VAR.  (19651)   NINE 

YEARS  FROM  ROOT-GRAFT 

This  species  is  erect  in  habit  when  young;  the  shoots 
bend  outward  when  fruiting  begins,  and  after  two  or 
three  crops  the  tops  become  wide-spreading.  The  tree 
shown  here,  from  a  root-graft  of  1907,  was  photographed 
when  nine  years  old. 


top-worked  tree  grafted  in  1912.  When  young  the  trees  are  erect  in 
habit;  when  fruiting  commences  the  long  willowy  shoots  are  bent 
outward;  and  after  bearing  two  or  three  crops  the  tops  become  wide- 
spreading.  The  tree  from  root-graft  in  1907,  as  photographed  Septem- 
ber 24,  1915,  when  nine  years  old,  is  shown  in  Fig.  74.  This  tree  as 
measured  in  the  fall  of  1923  is  17  feet  2  inches  high,  has  an  extreme 
spread  of  21  feet  2  inches,  and  a  trunk  diameter  of  8.6  inches.  The 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


543 


trunk  is  smooth  with  dark  cherry-like  bark,  twigs  very  dark  reddish- 
brown,  glabrous.  Lenticels  numerous  and  conspicuous. 


FIG.  75. — TWIG  OF  M.  prunifolia  VAR.   (19651)    IN 
BUD,  APHIL  21.   FIG.  76.— TWIG  IN 

FLOWER,  APRIL  30 

The  buds  are  dark  pink,  but  are  inconspicuous 
because  the  pedicels  and  bud  axis  are  short,  and 
leaves  hide  the  cluster.  As  flowering  continues,  the 
pedicels  and  bud  axis  elongate,  and  the  flowers  are 
thrust  out  beyond  the  leaves.  The  flowers  are  nearly 
pure  white  when  open. 


Leaves. — Three  to  4%  inches  long,  1  to  ll/2  inches  wide,  oval  or 
elliptical  or  some  of  the  smaller  approaching  lanceolate,  acute, 
coarsely  serrate,  glabrous  above,  sparingly  pubescent  along  the  midrib 
below;  petioles  stout,  mostly  about  an  inch  in  length,  glabrous. 


544 


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Flowers. — Borne  from  terminal  and  lateral  buds  on  terminal 
shoots.  Buds  dark  pink,  but  inconspicuous  in  early  stages  of  develop- 
ment because  pedicels  and  bud  axis  are  both  short  and  leaves  hide  the 
cluster ;  4  to  8,  mostly  5  buds  to  each  cluster.  As  development  proceeds 
the  bud  axis  elongates,  becoming  from  12  to  18  mm.  in  length;  the 


FIG.  77. — FRUITING  BRANCH  OF  M.  prunifolia  VAR. 
(19651),  SEPTEMBER  16 

This  form  retains  its  calyx  lobes  to  a  very  marked 
degree;  of  9,496  fruits  examined,  88  or  less  than  1  per- 
cent had  deciduous  lobes,  and  of  these  52  were  only 
partially  deciduous. 

pedicels  also  elongate,  reaching  22  to  30  mm.  in  length.  The  flowers 
are  thus  thrust  out  beyond  the  leaves  and  become  conspicuous;  they 
expand  about  30  mm.  and  are  nearly  pure  white  when  open.  Pedicels 
and  ovary  pubescent.  Calyx  lobes  triangular,  acute,  5  mm.  long,  2*4 
mm.  wide  at  base,  sparsely  pubescent  without,  densely  so  within,  erect 
in  bud,  becoming  reflexed  in  open  flowers.  Petals  elliptical,  16  mm. 
long,  8  mm.  wide,  with  short  claw.  Stamens  20,  filaments  slender,  8  to 
10  mm.  long,  anthers  plump,  light  yellow.  Styles  vary  from  3  to  5, 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  545 

are  8  to  10  mm.  long,  connate  %  the  length,  and  hairy  from  base  to 
point  of  separation.  Stigmas  oval,  more  or  less  oblique.  A  twig  in  bud 
is  shown  in  Fig.  75  and  one  in  flower  in  Fig.  76. 

Fruit. — Roundish  oblong;  the  average  of  4,000  fruits  weighs  4.63 
grams,  has  a  longitudinal  diameter  of  18  mm.,  a  transverse  diameter 
of  21  mm.,  and  produced  5.3  good  seeds.  Base  regular,  apex  irregular, 
clear  lemon-yellow  in  color;  covered  with  a  scanty,  waxy,  white 
bloom;  skin  smooth,  thin,  tough;  dots  few,  small,  white,  inconspicuous; 
stem  28  mm.  long,  slender,  erect,  green,  glabrous,  cavity  shallow,  nar- 
row, obtuse,  regular;  basin  none,  the  flesh  rounds  up  to  the  somewhat 
fleshy  bases  of  the  usually  persistent  calyx  lobes.  Very  few  of  the 
crab  forms  of  Malus  retain  the  calyx  lobes  with  as  high  constancy  as 
does  this;  of  9,496  fruits  examined  88  or  less  than  1  percent  are 
recorded  as  having  deciduous  lobes,  and  of  these  52  were  only  partially 
deciduous,  that  is  to  say,  while  2,  3,  or  4  of  the  lobes  dropped  off  leav- 
ing the  characteristic  scar,  there  remained  1,  2,  or  3  with  the  normal 
fleshy  bases.  Core  of  medium  size,  elliptical,  or  roundish,  median, 
closed.  Cells  axile,  carpels  obovate,  emarginate,  glabrous.  Seeds 
plump,  of  medium  size,  light  brown;  flesh  white,  firm,  crisp,  juicy,  very 
acid.  Fig.  77  showing  fruiting  characteristics  is  from  a  photograph 
made  September  16,  1915.  A  single  fruit  may  also  be  seen  at  the  left 
below  in  Fig.  54,  page  517. 

34.  Malus  ringo  (840,  19662) 

This  species  is  represented  both  as  No.  19662  in  the  series  pro- 
pagated in  1907  and  as  840  in  the  series  of  1908.  Trees  of  the  two 
numbers  are  alike  in  all  respects  and  probably  both  lots  of  scions  came 
from  the  same  tree.  Present  representation  in  the  collection  is  as 
follows: 

19662 — Two  trees  in  pots,  one  on  paradise,  one  on  Doucin,  grafted  Feb.  12, 

1910.    These  have  flowered  each  year  since  1913. 
One  tree,  in  pot,  on  paradise,  grafted  March  5,  1913. 
Five  trees  from  root-grafts  made  January  22,  1914. 
840 — Two  trees  from  root-grafts  made  January  18,  1908. 

One  tree  top-worked  on  Grimes,  April  6,  1912,  and  April  3,  1913. 

The  two  trees  from  root-grafts  of  1908,;  now  sixteen  .years  old, 
best  exhibit  the  habit  of  this  species.  They  are  symmetrical  trees 
with  erect  smooth  trunks  and  somewhat  spreading  round  tops.  The 
average  of  the  two  sixteen-year-old  trees  is  14  feet  7  inches  high, 
spread  23  feet,  and  has  trunk  diameter  of  6.7  inches.  The  bark  of 
trunk  and  branches  is  light  brown  with  an  olive-green  tinge ;  twigs  are 
reddish-brown,  glabrous.  The  tree  on  paradise  grafted  March  5,  1913, 
is  shown  as  photographed  June  21,  1916,  in  Fig.  78. 

Leaves. — Broadly  ovate  to  oblong  or  elliptical,  2%  to  4%  inches 
long,  1  to  2%  inches  wide,  serrate  or  coarsely  crenate-dentate,  acumi- 


546 


BULLETIN  No.  275 


[June, 


nate ;  when  young  densely  white  tomentose  beneath  and  with  scattered 
hairs  on  the  upper  surface,  becoming  glabrous  above,  but  retaining 
some  pubescence  below;  rather  thick  even  when  young,  becoming 
thicker  in  age  and  somewhat  rugose,  dull  green  above  and  but  little 
lighter  in  color  below.  Petioles  %  to  1  inch  long,  densely  pubescent 

when  young,  becoming  glabrous  in 
age;  stipules  lanceolate,  entire,  or 
with  occasional  serrations,  petio- 
late,  caducous. 

Flowers. — These  trees  have 
bloomed  yearly  since  1913  and 
every  second  year  since  1918  have 
flowered  profusely.  May  5  is  the 
mean  full  bloom  date  for  the  last 
twelve  years,  while  April  17,  1921, 
was  the  earliest,  and  May  17, 
1917,  the  latest  date  for  full  bloom. 
The  flower  clusters  come  princi- 
pally from  terminal  buds  of  shoots 
of  the  preceding  year  and  of  short 
spurs  along  the  larger  branches 
and  also,  to  some  extent,  from  lat- 
eral buds  of  terminal  shoots. 
There  is  no  crowding  of  clusters 
and  massing  of  bloom  as  in  most 
forms  of  M.  baccata  or  of  the 
forms  of  M.  prunifolia  thus  far 
described.  Flower  clusters  are 
scattered  over  the  trees  much  as 
they  are  in  the  native  species 
M.  ioensis.  Two-thirds  of  the 
clusters  examined  produced  5 
flowers  each,  but  the  range  in 
number  was  from  3  to  11.  Of  140 
clusters  1  had  3,  21  had  4  each, 
93  had  5  each,  20  had  6  each,  1 

had  8,  and  1  had  11.  Young  buds  are  nearly  globular  and  deep  red  in 
color;  as  they  develop  there  is  some  elongation  and  the  color  fades  to 
a  dark  pink.  Pedicels  stout,  15  to  28  mm.  long,  pubescent;  calyx  lobes 
short,  broadly  triangular,  obtuse,  pubescent  both  sides.  Petals  oval  or 
nearly  orbicular,  rounded  at  apex,  13  mm.  long,  10  mm.  wide,  claw 
short  but  distinct.  Flowers  expand  28  mm.  From  examination  of  250 
flowers  it  is  found  that  stamens  range  in  numbers  from  12  to  25  with 
an  average  to  each  flower  of  a  little  above  19.  Filaments  slender,  3 


FIG.  78. — TREE  OF  M.  ringo 

(19662)  ON  PARADISE 
This  tree  was  grafted  March  5, 1913, 
and  was  photographed  June  21,1916. 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


547 


to  6  mm.  long,  anthers  plump,  light  yellow,  containing  abundant  good 
pollen.  Styles  vary  in  number  from  3  to  6  with  an  average  of  4.82, 
slender,  8  to  9  mm.  long,  connate  %  the  length,  sparsely  hairy  about 
and  just  above  the  point  of  separation.  Stigmas  oval,  oblique.  Fig.  79 
is  a  twig  in  bud  as  photographed  in  the  greenhouse  March  13,  1914. 
Buds  expand  with,  or  a  little  in  advance  of,  the  leaves  and  because  of 
the  dark  red  color  are  conspicuous  and  handsome. 


FIG.  79.— TWIG  OF  M.  ringo  (840) 

IN  BUD,  MARCH  13 

Buds  expand  a  little  in  advance  of  the 
leaves;  they  are  dark  red  in  color  and  very 
ornamental. 


Fruit. — Fruits  are  in  clusters  of  from  3  to  6,  roundish  oblate, 
regular  at  base,  apex  irregular,  ribbed;  in  cross-section  most  fruits 
exhibit  5  well-marked  ridges;  sides  equal,  weight  and  dimensions  as 
averaged  from  301  fruits  are  as  follows;  weight  3.24  grams,  longitud- 
inal diameter  15  mm.,  transverse  diameter  18  mm.  The  average  seed 
production  as  found  from  these  same  fruits  is  5.79  seeds  to  each  fruit, 
a  number  considerably  above  the  average  for  the  crab  group.  The 
color  is  for  most  fruits  a  brilliant  crimson;  this  is  blushed  or  washed 


548 


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on  over  a  greenish-yellow  ground  which,  for  most  fruits,  is  entirely 
obscured.  This  high  color  adds  much  to  the  attractiveness  of  the  tree 
in  autumn,  but  the  beauty  is  fleeting  because  soon  after  acquiring  the 
brilliant  color  the  fruits  fall. 

A  moderately  heavy,  waxy,  white  bloom  covers  the  fruits;  skin 
smooth,  thin,  tough;  dots  few,  small,  regular,  round,  white,  inconspicu- 
ous; cavity  rather  shallow,  broad,  obtuse,  regular;  stem  stout,  15  to 
25  mm.  long,  erect,  pubescent.  Basin  shallow  broad,  obtuse,  irregular, 


FIG.  80. — TWIG  OF  M .  ringo  IN  FRUIT,  AUGUST  20 
Fruits  appear  in  clusters  of  three  to  six;   most  of  them  are  a 
brilliant  crimson,  making  the  tree  very  attractive  for  a  short  period 
in  autumn.    The  fruits  fall  soon  after  acquiring  this  brilliant  color. 


ribbed ;  the  calyx  lobes  are  deciduous  as  determined  from  examination 
of  1,401  fruits,  but  in  many  of  the  fruits  the  dehiscence  is  somewhat 
tardy ;  separation  takes  place,  but  the  dried  calyx  still  persists  until  in 
some  way  disturbed.  The  dried  lobes  are  readily  brushed  off  and  then 
show  the  characteristic  russet  scar.  The  core  is  large,  cordate,  median, 
closed;  cells  axile,  carpels  obovate,  emarginate,  glabrous,  usually 
deeply  concave;  flesh  yellowish,  firm,  crisp,  juicy,  acid.  Two  clusters 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  549 

of  fruits,  from  pollinations  made  in  the  spring,  are  shown  as  photo- 
graphed August  7,  1914,  in  Fig.  80.  A  single  fruit  is  also  shown  second 
from  the  right  in  Fig.  73,  page  541.  The  characteristics  of  M.  ringo 
indicate  a  hybrid  origin.  Leaf  and  tree  characters  most  resem- 
ble M.  prunifolia,  but  the  fruit  characters,  particularly  in  regard  to 
the  deciduous  calyx,  point  to  M.  baccata  as  one  of  the  probable 
progenitors.  It  was  introduced  in  Europe  more  than  fifty  years  ago  by 
Dr.  von  Siebold,  coming  as  a  cultivated  plant  from  Japan.  How  long 
it  had  been  under  cultivation  there,  what  species  it  had  opportunity  to 
mingle  with,  or  how  many  generations  of  seedlings  preceded  the  pres- 
ent form  are  matters  unknown  and  past  finding  out.  The  history  of  the 
plant  is  entirely  unknown  and  possible  ancestors  can  only  be  assumed 
from  study  of  the  characters  possessed  by  the  plant  as  it  now  exists. 

35.  Mains  ringo  sublobata  (854,  19689) 

Scions  of  this  form  of  Malus  were  received  from  the  Arnold  Ar- 
boretum thru  the  U.  S.  Department  of  Agriculture,  in  1907,  under  the 
number  19689.  Other  scions  were  received  in  1908  direct  from  the  Ar- 
boretum, but  under  the  name  Malus  toringo  sublobata.  This  went  into 
the  Station  collection  under  the  serial  number  854.  The  trees  grown 
from  the  two  lots  of  scions  were  carried  in  the  records  under  the  re- 
spective numbers  until  flowers  and  fruit  were  produced,  when  it 
became  evident  that  the  two  were  identical.  Later  the  identity  of  the 
plants  grown  here  with  the  original  tree  in  the  Arnold  Arboretum 
under  the  name  Malus  ringo  sublobata  was  established.  This  tree  in 
the  Arboretum  was  received  from  Germany  about  twenty-five  years 
ago  as  Pyrus  ringo  sublobata.  It  was  transferred  to  the  genus  Malus, 
and  recently  Dr.  Alfred  Rehder  has  determined  it  as  Malus  prunifolia 
rinki,  basing  this  determination  upon  material  collected  in  Japan  in 
1914  by  Professor  J.  G.  Jack.  Representation  in  the  collection  is  as 
follows: 

19689 — One  tree  from  root-graft  made  January,  1907,  and  now  seventeen 

years  old. 

Two  trees  from  root-grafts  made  in  1914. 

854 — Two  trees  from  root-grafts  made  January,  1908,  and  one  tree  top- 
worked  on  Virginia  Crab  in  1908. 

Trees  of  erect  habit,  branches  numerous,  inclined  to  be  long  and 
slender^  in  fruit  curving  outward  and  bending  low.  Bark  of  trunk  and 
branches  smooth,  light  brown  with  a  distinct  tinge  of  olive-green;  twigs 
dark  reddish-brown,  glabrous.  The  tallest  tree  measures  15  feet,  has  a 
spread  of  14  feet  5  inches  and  a  trunk  diameter  of  6.1  inches;  dimen- 
sions of  other  trees  are  but  slightly  less.  One  of  these  trees  as  photo- 
graphed September  24,  1915,  is  shown  in  Fig.  81. 

Leaves. — Ovate,  oblong  or  elliptical,  some  of  the  small  ones  lance- 
olate, 2  to  4  inches  long,  %  to  1%  inches  wide;  irregularly  coarsely 


550 


BULLETIN  No.  275 


[June, 


serrate,  acute  or  shortly  acuminate,  densely  white  tomentose  below 
and  with  some  scattered  hairs  above  when  young,  becoming  glabrous 
both  above  and  below.  Petioles  %  to  1  inch  long,  stout,  pubescent 


FIG.  81.— TREE  OF  M.  ringo  sublobata  (19689) 

NINE  YEARS  FROM  ROOT-GRAFT 

The  tallest  tree  of  this  species  now  growing  at  this 
Station  is  15  feet  high,  and  has  a  spread  of  14  feet  5 
inches;  the  others  are  slightly  smaller.  The  one  shown 
here  was  photographed  September  24,  1915. 


when  young,  becoming  glabrous.   Stipules  %  to  %  inch  long,  lanceo- 
late, petiolate,  persisting  on  some  leaves. 

Flowers. — Young  plants  flower  first  from  terminal  buds,  the  sec- 
ond year  of  flowering  a  few  lateral  buds,  usually  just  below  the  ter- 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


551 


minal  bud,  produce  flowers;  this  flowering  portion  of  the  shoot  becomes 
longer  each  year,  in  some  cases  approximating  2  feet  in  length.  The 
internodes  are  short,  bringing  clusters  near  together,  thus  massing  the 


FIG.  82. — TREE  OF  M.  ringo  sublobata  (854-4)  IN 
FLOWER  MAY  9,  1916 

The  flowering  portion  of  the  shoot  (the  terminal  bud 
and  a  few  adjoining  lateral  buds)  becomes  longer  each 
year,  in  some  cases  reaching  a  length  of  nearly  two  feet. 
The  internodes  are  short,  bringing  the  clusters  near 
together  and  massing  the  bloom  attractively. 


bloom  and  adding  to  the  attractiveness  of  the  tree  when  in  xfull  bloom. 
Fig.  82  illustrates  one  of  the  trees  as  it  appeared  when  photographed 
May  9,  1916.  In  bud  the  pedicels  are  short  and  the  buds  obscured  by 
the  young  leaves;  later  the  pedicels  elongate  and  become  an  inch  or 
more  in  length  by  the  time  the  flowers  are  open.  Buds  are  oblong, 
rounded  at  apex,  dark  reddish-pink;  the  nunater  in  each  cluster  is  var- 
iable and  has  rather  an  extreme  range,  from  2  to  16.  In  579  clusters 
examined  the  distribution  was  as  follows: 


552  BULLETIN  No.  275  [June, 

Number  of  buds  to  the 

cluster 234       5        6       7      8      9     10   11  12  14  15  16 

Number  of  clusters 2    3    32     134    230    88     36    28     12    6    4     1     1     2 

The  petals  fade  as  the  buds  open  and  when  the  flowers,  which  expand 
about  30  mm.,  are  fully  open  they  are  white,  somewhat  streaked  with 
light  pink.  Calyx  lobes  5,  triangular  acuminate,  5  mm.  long  and  2  mm. 
wide  at  base,  pubescent  both  sides,  erect  in  bud,  becoming  reflexed  in 
open  flowers.  Petals  5  to  7,  ovate  to  elliptical  with  short,  but  distinct 
claws.  Stamens  8  to  10,  filaments  slender,  4  to  8  mm.  long,  anthers 
plump,  light  yellow;  styles  4  or  5,  slender,  about  8  mm.  long,  connate 
y4  the  length,  hairy  from  base  to  above  the  point  of  separation. 
Stigmas  oval,  oblique,  and  somewhat  prolonged  down  the  style. 

Fruit  in  clusters  of  2  to  5,  oblong,  conical,  regular  at  base  and 
apex,  cross-section  obscurely  ribbed,  sides  equal.  The  average  weight 
and  dimensions  as  determined  from  5,800  fruits  are  as  follows: — 
weight  6.33  grams,  longitudinal  diameter  22.91  mm.,  transverse  diam- 
eter 22.52  mm.  Color  dull  yellow,  sometimes  with  bronze  blush  on  one 
side,  a  moderate  amount  of  waxy  white  bloom.  Skin  rough  with  irreg- 
ular russet  dots  and  splashes.  Cavity  medium  in  depth,  rather  nar- 
row, acute;  stem  short,  13  to  25  mm.  long,  slender,  glabrous.  Basin 
in  fruits  having  deciduous  calyx  lobes  is  represented  by  a  very  slight 
depression  which  is  narrow  and  obtuse;  in  fruit  with  persistent  calyx 
lobes  the  surface  rounds  up  to  the  fleshy  bases  of  the  lobes  and  there 
is  entire  absence  of  depression. 

In  the  matter  of  retention  of  calyx  lobes  there  is  a  division  in  this 
form  of  Malus;  in  some  fruits  they  persist  while  in  others  they  are 
deciduous.  In  1915,  1,943  fruits  were  examined  in  regard  to  this  char- 
acter and  438  or  22.54  percent  found  to  be  deciduous.  In  1917  all 
available  fruits  were  examined  and  the  record  for  each  of  eleven  trees 
was  kept  separately.  The  numbers  of  fruits  for  individual  trees  range 
from  373  for  a  tree  top-worked  in  1912  to  4,998  for  a  tree  root-grafted 
in  1908.  The  aggregate  of  fruits  is  23,671,  and  of  this  number  6,666  or 
28.16  percent  have  regularly  deciduous  calyx  lobes. 

All  of  the  trees  from  which  these  fruits  were  taken  were  propa- 
gated by  grafting  from  a  single  individual,  and  it  seems  reasonable  to 
expect  uniformity  in  the  proportion  of  fruits  having  deciduous  calyx 
lobes,  but  the  individual  trees  vary  greatly  in  this  respect.  While  the 
percentage  of  fruits  with  deciduous  calyx  lobes  is  for  all  fruits  28.16, 
for  individuals  the  range  is  from  14.28  percent  for  a  tree  having  2,234 
fruits  and  15.46  percent  for  a  tree  having  3,831  fruits  to  57.13  percent 
for  a  tree  having  4,998  fruits.  Of  the  eleven  trees  four  are  each  less 
than  20  percent  deciduous,  five  have  percentages  between  20  and  30, 
one  has  36.73  percent,  and  one  has  57.13  percent.  This  appears  to  be 
a  very  wide  range  of  differences  for  so  distinctive  a  character  and  as 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


553 


yet  no  satisfactory  explanation  has  suggested  itself.  Core  of  medium 
size,  elliptical,  median,  closed;  cells  axile,  carpels  ovate  to  oblong, 
sometimes  obovate,  emarginate,  glabrous,  moderately  concave,  seeds 
plump,  of  medium  size,  color  a  medium  brown.  The  fruits  are  quite 
low  in  seed  production;  as  averaged  from  5,800  fruits  there  are  3.61 
seeds  to  each  fruit.  Only  two  of  the  crab  group  fall  below  this  average, 
namely — M.  jusca,  with  an  average  of  1.32,  and  M.  atrosanguinea, 
with  an  average  of  2.02  seeds 
to  each  fruit.  The  average  for 
all  fruiting  crabs  in  the  col- 
lection is  4.22  seeds  to  each 
fruit.  Flesh  yellowish,  firm, 
crisp,  rather  dry,  acid.  Fig. 
83  is  from  a  photograph  taken 
September  16,  1915.  M.  ringo 
sublobata,  under  the  two 
numbers  19689  and  854,  has 
served  as  the  female  parent 
in  twenty-eight  crosses,  nine 
on  trees  in  orchard  and  nine- 
teen in  the  greenhouse.  Six- 
teen varieties  and  three  crab 
forms  were  used  as  male  par- 
ents. The  aggregate  of  polli- 
nations made  was  2,013,  and 
897  fruits  representing  44.56 
percent  of  the  pollinations 
matured.  For  individual 
crosses  the  percentage  of  suc- 
cess ranged  between  24.1  per- 
cent and  100  percent.  The 
degree  of  success  attained  was 
high  and  this  form  may  be 
rated  as  successful  as  a  fe- 
male parent.  The  variety  is 

not  available  as  a  male  parent  because  it  produces  no  viable  pollen. 
Anthers  removed  from  flowers  dry  up  and  do  not  dehisce;  when 
broken  mechanically  no  fully  developed  pollen  grains  are  found. 

An  abnormality  not  found,  or  at  least  of  very  rare  occurrence,  in 
other  forms  of  Malus  is  quite  common  in  this  variety  and  that  is  the 
production  of  2  or  in  some  cases  3  flowers  on  the  same  pedicel.  This 
occurs,  with  rare  exceptions,  in  terminal  clusters.  The  point  of  branch- 
ing varies  greatly;  most  frequently  it  is  near  the  distal  extremity  of 
the  pedicel,  but  sometimes  occurs  near  the  middle  or  in  some  cases 
near  the  base.  Where  branching  occurs  near  the  end  of  the  pedicel  the 


FIG.  83. — FRUITING  TWIG  OF  M.  ringo 
sublobata,  SEPTEMBER  16 


654 


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[June, 


FIG.  84. — TWIN  FRUITS  OF  M.  ringo  sublobata  (854), 
SEPTEMBER  14 

This  abnormality  appears  as  a  characteristic  of  the  variety. 
Nearly  200  cases  of  this  union  of  fruits  following  the  appearance 
of  flowers  on  branches  of  pedicels  are  recorded  for  this  variety  of 
Malus  in  1916,  and  none  for  any  other  variety.  The  twinned  fruits 
are  sometimes  equal  in  size,  but  often  the  fruit  terminating  the 
pedicel  is  larger  than  that  terminating  the  branch. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  555 

ovaries  are  in  such  close  contact  that  they  invariably  grow  together; 
the  area  involved  in  the  union  is  greater  or  less  according  to  the  posi- 
tions occupied  by  the  ovaries  and  the  length  of  the  pedicel  branch.  In 
some  cases  a  branch  is  so  short  as  to  become  entirely  imbedded  in  the 
developing  fruits  which  then  take  a  nearly  horizontal  position  with 
the  apexes  at  the  extreme  of  possible  separation;  in  other  cases  the 
branches  are  long  enough  to  remain  free  and  the  apexes  of  the  fruits 
point  obliquely  downward  and  vary  in  degree  of  separation  according 
to  the  extent  of  the  union.  Where  the  branches  are  long  no  union  of 
ovaries  takes  place  and  sometimes  the  two  fruits  developed  on  the  one 
pedicel  are  equal  and  normal  in  size.  Equality  in  size  of  twinned  fruits 
is  not  rare,  but  in  many  pairs  the  fruit  terminating  the  pedicel  is 
larger  than  that  terminating  the  branch.  Not  infrequently  the  fruit  on 
the  branch  remains  quite  small  and  cases  are  found  in  which  the  small 
fruit  becomes  almost  entirely  invested  by  the  larger.  Nearly  200  cases 
of  this  union  of  fruits  following  the  appearance  of  flowers  on  branches 
of  pedicels  are  recorded  for  this  variety  of  Malus,  in  1916,  and  none 
for  any  other  variety.-  The  abnormality  appears  as  a  characteristic  of 
the  variety.  Several  forms  of  these  united  fruits  are  shown  in  Fig.  84. 
which  is  from  a  photograph  made  September  14,  1915. 

36.  Malus  sargenti  Rehder.    Sargent,  C.  S.    Trees  and  Shrubs  1, 

p.  71.    1905 

Represented  in  the  collection  by  one  tree  from  root-graft  made 
January  11,  1908,  now  in. its  seventeenth  year;  a  small  and  shrub-like 
tree  7  feet  2  inches  high,  with  a  spread  of  12  feet  9  inches,  and  a  trunk 
diameter  of  5.1  inches.  The  tree  has  flowered  and  fruited  abundantly 
each  year  since  1913.  Its  appearance  when  nine  years  old  as  photo- 
graphed May  9,  1916,  is  shown  in  Fig.  85.  There  is  also  one  tree  top- 
worked  on  Virginia  Crab,  April  8,  1908,  and  one  tree  grafted  in  Febru- 
ary, 1910,  on  potted  Doucin  stock.  This  dwarf  tree  in  greenhouse  has 
flowered  each  year  since  1913  and  has  been  used  in  crosses.  The  tree 
on  Virginia  Crab  as  it  appeared  four  years  from  grafting  is  shown  in 
Fig.  86  from  photograph  October  25,  1911. 

Low,  thick,  shrubby  growth  with  somewhat  tortuous  branches  is 
characteristic  of  this  species.  Bark  of  trunk  and  large  branches  dark 
brown,  conspicuously  marked  with  numerous  large,  dull  straw-colored, 
transversely  elongated  lenticels;  twigs  and  smaller  branches  reddish- 
brown. 

Leaves. — Leaves  of  flowering  shoots  small  and  extremely  variable 
in  form,  from  narrowly  lanceolate  to  ovate,  elliptical,  and  even  orbic- 
ular, sharply  serrate  or  often  nearly  entire  on  the  lower  half.  On  non- 
flowering  shoots  ovate  or  oblong-ovate,  or  some  of  the  smaller  ellip- 
tical, 1%  to  3%  inches  long,  %  inch  to  2%  inches  broad;  many  are 


556 


BULLETIN  No.  275 


[June, 


3-lobed,  the  central  lobe  much  larger  than  the  two  lateral  lobes  and 
sometimes  this  is  so  notched  above  as  to  give  the  appearance  of  5 
lobes;  irregularly  sharply  serrate,  apex  acute,  base  rounded,  often  sub- 
cordate;  sparingly  pubescent  both  sides  when  young,  becoming  gla- 
brous above  and,  in  the  fall,  sparsely  villous  below.  Petioles  slender, 
Y2  to  1  inch  long,  pubescent  wrhen  young,  but  nearly  glabrous  when 


FIG.  85. — TREE  OF  M.  sargenti  (843) 

NINE  YEARS  OLD 

From  root-graft  made  January  11,  1908.  This 
tree,  which  was  photographed  May  9,  1916,  has 
flowered  and  fruited  abundantly  each  year 
since  1913. 


mature;  stipules  minute  and  caducous  below,  on  leaves  above,  folia- 
ceous,  lanceolate,  remotely  serrate,  inclined  to  persist. 

Flowers. — Produced  in  profusion  from  terminal  and  lateral  buds 
of  spurs  and  twigs;  the  number  of  buds  to  a  cluster  was  as  follows 
for  30  clusters  counted;  with  3  buds  1,  with  4  buds  1,  with  5  buds  4, 
with  6  buds  17,  with  7  buds  6,  and  with  8  buds  1.  The  buds  are  red- 
dish-pink at  first,  but  soon  fade;  each  petal  becomes  white  except  at 
the  margin  which  retains  the  pink,  imparting  to  the  buds  a  striped 
appearance  that  is  quite  characteristic ;  another  peculiarity  that  serves 
to  distinguish  readily  the  buds  of  this  species  from  those  of  any  other 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


557 


Malus  in  the  collection  is  the  folding  in  of  the  tips  of  the  petals  at 
nearly  a  right  angle,  giving  a  truncated  or  flat-topped  appearance. 
Frequently  the  styles  protrude  in  the  center  while  the  buds  are  quite 
young.  Flowers  expand  18  to  20  mm.  Pedicels  are  slender,  20  to  25 
mm.  long,  green,  sparsely  pubescent;  the  ovaries  are  glabrous.  Calyx 
lobes  rather  broadly  triangular,  acuminate,  4  mm.  long-  and  2  mm. 


FIG.  86.— TOP-WORKED  TREE  OF  M .  sargenti  (843) 
FOUR  YEARS  FROM  INSERTION  OF  SCIONS 

This  tree  is  characteristically  low,  thick,  and  shrubby 
in  growth,  with  somewhat  tortuous  branches.  The  bark 
of  the  trunk  and  large  branches  is  dark  brown,  marked 
with  large,  straw-colored,  crosswise  lenticels. 


broad  at  base,  glabrous  outside,  pubescent  on  margins  and  inside,  erect 
in  bud,  becoming  about  horizontal  in  open  flowers;  tips  are  not  re- 
flexed  ;  the  calyx  lobes  are  regularly  deciduous  soon  after  the  flowering 
period.  To  obtain  more  definite  information  regarding  the  constancy 
of  this  character  of  deciduous  calyx  lobes,  1,000  fruits  were  examined 
with  special  reference  to  the  calyx  lobes  without  bringing  to  light  any 
departure  from  regular  deciduousness  either  in  time,  manner,  or  char- 


558 


BULLETIN  No.  275 


[June, 


acter  of  the  scar  left;  the  lobes  are  deciduous  in  all  fruits  and  in  the 
same  way:  evidently  the  species  is  pure  as  to  this  character.  Petals 
5,  oblong  or  oval,  rounded  at  apex,  9  mm.  long,  5  mm.  broad,  sub- 
cordate,  claw  short,  but  distinct,  1  mm.  long.  Stamens  18  to  20,  fila- 
ments rather  stout,  3  to  6  mm.  long;  anthers  plump,  yellow,  pollen 

orange.  Styles  3  to  5,  most  com- 
monly 4,  7  mm.  long,  connate  for 
2  mm.  from  base  and  glabrous 
except  for  a  narrow  ring  of  hairs 
immediately  about  the  point  of 
separation ;  stigmas  irregularly 
oval,  oblique.  Fig.  87  is  from  pho- 
tograph of  a  twig  of  this  species 
in  bud. 

Fruit. — Round,  regular  at  base 
and  apex  in  transverse  section, 
sides  equal.  The  average  of  223 
fruits  weighed  and  measured  is  a 
fruit  weighing  .56  gram,  with  a 
longitudinal  diameter  of  8%  mm. 
and  a  transverse  diameter  of  9% 
mm.  These  fruits  had  cells  as  fol- 
lows: with  2  cells  1,  with  3 
cells  22,  with  4  cells  141,  with  5 
cells  59.  Color  a  uniform  dark  red, 
becoming  very  dark,  almost  black 
in  late  fall.  After  frosts  the  fruits 
become  very  soft  and  soon  dis- 
solve and  disappear,  leaving  the 
pedicels  upon  the  tree.  Skin 
smooth,  of  medium  thickness, 
tough;  dots  few,  small,  regular, 
round,  gray,  inconspicuous;  cavity 
shallow,  moderately  broad;  acute, 
regular;  stem  long,  20  to  25  mm., 
slender,  erect,  green,  glabrous; 

calyx  lobes  uniformly  deciduous ;  basin  shallow,  broad,  obtuse,  slightly 
ribbed.  Core  of  medium  size,  elliptical,  median,  closed;  carpels 
roundish,  entire,  glabrous,  moderately  concave;  flesh  yellowish,  rather 
dry  until  touched  by  frost,  then  becoming  watery,  acid. 

A  fruiting  branch,  %  natural  size,  is  shown  in  Fig.  88  from  photo- 
graph of  October  18,  1916,  and  a  single  fruit  appears,  natural  size,  the 
fourth  from  the  left  in  Fig.  44,  page  498,  where  comparison  is  afforded 
with  fruits  of  several  other  species.  This  species  was  discovered  by 
Dr.  C.  S.  Sargent  in  a  "brackish  marsh  near  Mororan,  Japan,  in  1892 


FIG.  87.— TWIG  OF  M.  sargenti  (843) 

IN  BUD,  MARCH  19 
The  buds  have  a  characteristic 
pink  and  white  striped  appearance ; 
they  are  also  distinguished  easily 
from  those  of  any  other  Malus  in 
the  collection  by  the  folding  in  of  the 
tips  of  the  petals  at  nearly  a  right 
angle,  which  gives  them  a  flat- 
topped  appearance. 


1926] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


559 


and  introduced  by  him  into  cultivation."  It  was  described  and  named 
by  Dr.  Alfred  Rehder  and  published  by  Dr.  C.  S.  Sargent.1  Affinities 
of  the  species  are  given  by  Dr.  Rehder  as  follows: 

"Malus  Sargenti  is  most  nearly  related  to  Mains  Toringo  Sieboldi,  differing 
from  it  chiefly  in  its  larger,  pure  white,  flowers,  with  broad  subcordate  petals 
overlapping  each  other,  and  in  the  larger  fruits.  From  Pyrus  (Malus)  Zumi, 
Matsumura,  which  is  also  closely  related  to  Malus  Toringo,  Malus  Sargenti  may 
be  distinguished  by  the  broader,  often  lobed  leaves,  the  shape  of  the  petals,  the 
glabrous  calyx-tube  and  the  habit." 

This  species  appears  as  the  female  parent  in  thirteen  crosses 
attempted  with  pollen  of  eight  varieties.  The  290  pollinations  matured 


FIG.  88. — FRUITING   BRANCH   OF   M.  sargenti   (843) 
ONE-SIXTH  NATURAL  SIZE,  PHOTOGRAPHED 

OCTOBER  18 

The  fruits  are  a  uniform  dark  red,  becoming 
very  dark,  almost  black,  in  late  fall.  After  frosts 
the  fruits  become  very  soft,  and  then  dissolve 
and  disappear,  leaving  the  pedicels  upon  the  tree. 

120  fruits  representing  41.37  percent  of  the  pollinations.  Two  crosses, 
those  by  Stayman  Winesap  and  Fanny,  failed  in  fruit  production. 
Nine  of  the  remaining  crosses,  altho  maturing  fruits  from  52.27  percent 
of  the  pollinations,  failed;  seven  because  of  failure  of  seeds  to  germ- 
inate and  two  because  seedlings  had  no  vitality  and  died  immediately 
after  appearance.  Thus  only  two  crosses  have  representation  in 


'Sargent,  C.  S.  Trees  and  Shrubs  1,  71.  1905. 


560  BULLETIN  No.  275  [June, 

orchard:  (1)  The  cross  by  Grimes  in  greenhouse  in  1914,  in  which  15 
pollinations  matured  10  fruits  containing  21  seeds,  12  of  which  germ- 
inated. Five  seedlings  were  transferred  to  nursery  and  one  is  now  living 
in  its  tenth  year;  this  tree  is  5  feet  high,  spreads  8  feet,  has  a  diam- 
eter of  2.1  inches,  and  grades  as  "good."  (2)  The  cross  by  Yellow 
Transparent  in  greenhouse  in  1917,  in  which  31  pollinations  matured  18 
fruits  containing  43  seeds,  2  of  which  germinated ;  one  seedling  is  living 
in  its  seventh  year,  is  2  feet  8  inches  high,  spreads  3  feet  2  inches,  has 
a  diameter  of  1.2  inches,  and  grades  as  "fair."  Results  do  not  en- 
courage further  use  of  this  species  as  a  female  parent.  As  the  pollen 
parent,  M.  sargenti  was  used  in  four  crosses;  three,  on  Stayman 
Winesap,  Jonathan,  and  Lady  with  20  pollinations  failed.  A  cross  on 
M.  siberica  (19643)  in  greenhouse  in  1914,  from  13  pollinations  ma- 
tured 8  fruits  containing  48  seeds,  6  of  which  germinated;  three  seed- 
lings went  to  nursery  and  two  are  now  living  in  their  tenth  year ;  they 
average  7  feet  10  inches  in  height,  10  feet  10  inches  in  spread,  and  2.9 
inches  in  diameter  and  grade  as  "good." 

37.  Mains  scheideckeri  (19646) 

Scions  received  from  the  Arnold  Arboretum  thru  the  U.  S.  De- 
partment of  Agriculture,  January,  1907,  under  the  accession  number 
19646,  which  number  has  been  retained.  This  is  probably  a  hybrid 
altho  there  appears  to  be  uncertainty  as  to  the  species  combined.  The 
Department  of  Agriculture  list  accompanying  the  scions  follows  the 
name  scheideckeri  with  this  remark:  "A  very  fine  seminal  form  of 
the  double  M.  spectabUis."  Records  at  the  Arnold  Arboretum  state 
that  the  plant  was  received  from  a  German  nursery  in  1889  as  Pyrus 
spectabUis  X  floribunda  scheideckeri.  Later  it  was  renamed  Mains 
scheideckeri.  On  herbarium  mounts  expression  is  given  to  the  opinion 
that  the  plant  is  a  hybrid  between  Mains  floribunda  and  Mains  pruni- 
folia.  The  London  Journal  of  Horticulture  states,1  "Pyrus  Schei- 
deckeri is  a  supposed  hybrid  between  spectabUis  and  Toringo  and  is 
closely  allied  to  floribunda  and  baccata."  Alliance  to  Mains  spectab- 
Uis is  suggested  by  a  more  or  less  marked  tendency  to  multiplication 
of  floral  parts;  to  toringo  or  to  floribunda  by  the  large  number  of 
fruits  having  deciduous  calyx  lobes ;  and  to  prunifolia  by  the  fact  that 
many  fruits  have  a  regularly  persistent  calyx.  Definite  information 
regarding  origin  of  this  form  does  not  appear  to  be  available,  and  the 
names  applied  must  be  taken  as  expressions  of  judgment  on  the  part 
of  those  who  use  the  names  in  question. 

This  species  is  represented  in  the  Station  collection  by  one  tree 
grown  from  root-graft  made  March  23,  1907.  This  tree  at  seventeen 


'Journal  of  Horticulture  and  Home  Farmer  55,  34.    1907. 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


561 


\ 


years  of  age  is  15  feet  high,  has  a  spread  of  11  feet  3  inches,  and  a 
trunk  diameter  of  5.1  inches.  Scions  from  this  tree  have  been  used  for 
further  propagation  to  increase  the  representation  of  the  species  and 
five  trees  grafted  in  1914  average,  in 
their  tenth  year,  12  feet  2  inches  in 
height,  9  feet  in  spread,  and  3.76  inches 
in  diameter.  There  are  also  three  trees 
on  dwarf  stocks  in  greenhouse,  one  grafted 
on  Doucin  in  1910  and  two  on  paradise, 
one  from  graft  of  1913,  the  other  from 
graft  of  1918.  The  tree  grafted  in  1907 
began  flowering  in  1911  and  has  for  sev- 
eral years  given  abundant  bloom  each 
year.  The  dwarfs  in  greenhouse  bloom 
abundantly  and  have  been  freely  used 
in  crossing.  In  habit  the  tree  is  erect,  as 
is  shown  in  Fig.  89.  The  trunk  and  larger 
branches  have  smooth,  light  brown  bark 
and  the  twigs  are  reddish-brown.  The  len- 
ticels  are  numerous  and  conspicuous. 

Leaves. — Various,  on  spurs  and  flow- 
ering shoots  they  are  elliptical,  oblong  or 
lanceolate;  on  terminal  non-flowering 
shoots  larger  and  broader,  ovate  or  ob- 
long; they  are  from  2%  to  4%  inches  long 
and  1  to  2  inches  wide,  acuminate,  mostly 
irregularly  sharply  serrate,  scantily  pub- 
escent on  both  sides  when  young,  becom- 
ing glabrous  above;  petioles  rather  slen- 
der, pubescent.  Stipules  lanceolate,  acum- 
inate, serrate,  petioled,  retained  by  a  con- 
siderable portion  of  the  leaves. 

Flowers. — Produced  in  profusion  from 
terminal  and  lateral  buds  on  terminal 
shoots  and  to  some  extent  from  terminal 
buds  of  spurs  on  central  and  lower 
branches.  The  number  of  flowers  in  each 
cluster  is  extremely  variable:  for  196 
clusters  examined,  the  distribution  was: 


FIG.  89. — DORMANT  TREE  OF 
M.  scheideckeri  (19646) 
This  tree,  which  was 
grown  from  root-graft  of 
March  23,  1907,  was  photo- 
graphed during  the  dor- 
mant season  of  1913-1914. 
It  is  erect  in  habit,  and  has 
bloomed  abundantly  each 
year  since  1911. 


Number  of  flowers  to  cluster 2    3    4     5 

Number  of  clusters  with  flowers  as  above ...   1     8    6    20 


6      7      8     9    10 

44    71     40    4    2  =  196 


Flowers  expand  30  to  35  mm.    Pedicels  slender,  30  mm.  long,  pubes- 
cent.   Calyx  lobes  5,  triangular,  acute,  pubescent  both   sides,  tips 


562 


BULLETIN  No.  275 


[June, 


reflexed  in  open  flowers.  Petals  variable  in  number,  size  and  form.  In 
flowers  having  the  normal  number  of  petals  they  are  20  mm.  long  and 
11  mm.  wide;  in  flowers  in  which  there  is  some  multiplication  they 

are  somewhat  smaller.  Commonly  they 
are  elliptical,  but  frequently  oblong  or 
obovate.  In  one  lot  of  45  flowers  exam- 
ined the  range  in  number  was  from  5  to 
14  with  an  average  of  9;  in  another  lot  of 
112  flowers  the  range  was  from  4  to  9 
with  68  percent  having  the  normal  number 
of  5  and  an  average  for  the  lot  of  5%. 
Young  buds  are  globular,  deep  red,  be- 
coming considerably  elongated  before  op- 
ening. Where  the  petals  are  increased  in 
number,  it  is  only  those  of  the  outer 
whorl  that  are  colored  and  these  fade  to 
nearly  white  when  fully  expanded.  De- 
velopment and  expansion  of  petals  usually 
proceeds  slowly  and  it  is  frequently  the 
case  that  styles  protrude  from  the  apex 
of  unopened  buds  one  to  three  days  in  ad- 
vance of  anthesis;  this  feature  is  espe- 
cially apparent  on  trees  forced  under  glass, 
but  also  occurs  in  the  orchard,  at  least  in 
some  seasons.  The  protruded  stigmas  are 
receptive  and  as  this  occurs  well  in  ad- 
vance of  dehiscence  of  anthers,  the  flow- 
ers are  markedly  protogynous.  Petaloid 
stamens  are  quite  common;  over  60  per- 
cent of  the  flowers  examined  had  them  in 
numbers  from  1  to  7.  Stamens  with  an- 
thers are  numerous,  ranging  for  the  112 
flowers  examined  from  24  to  44  with  an 
average  of  35.3;  filaments  slender,  4  to 
10  mm.  long,  anthers  plump,  of  long  form, 
light  yellow.  Styles  range  in  number  from 
4  to  11  with  an  average  of  7,  slender,  8  to 
10  mm.  long,  connate  %  the  length,  glab- 
rous at  base,  but  with  a  few  hairs  in  a 
ring  about  the  point  of  separation.  Where 
the  number  of  styles  is  high,  usually  a 
portion  of  them  are  small,  very  slender, 

and  probably  unable  to  function.  Stigmas  oval  or  orbicular,  oblique. 
Fig.  90  from  photograph  of  a  twig  with  young  buds,  taken  in  the 
greenhouse  March  9,  1914,  shows  length  of  pedicels  and  relative  size 


FIG.     90. — BRANCH     OF     M. 

scheideckeri  (19646)  FROM 

TREE  IN  GREENHOUSE 

IN  BUD  MARCH  9 
Development  of  buds  of 
this  species  is  usually  rather 
slow,  and  frequently  styles 
protrude  from  the  apex  of 
unopened  buds  one  to  three 
days  before  full  bloom.  The 
branch  illustrated  here  shows 
the  length  of  pedicels  and 
relative  size  of  leaves  and 
buds  at  this  stage.  The  pro- 
truded stigmas  are  receptive, 
but  since  they  occur  before 
the  dehiscence  of  anthers, 
the  flowers  are  protogynous 
to  a  marked  degree. 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  563 

of  leaves  and  buds  at  this  stage  of  development;  some  of  the  buds 
have  the  protruding  stigmas  referred  to  altho  rather  indistinctly 
shown.  Fig.  91  is  from  a  photograph  of  a  branch  from  the  tree  in 
orchard,  taken  April  30,  1915,  and  serves  to  illustrate  the  massing 
of  color  due  to  the  close  proximity  of  the  bud  clusters  and  also  shows 
how  completely  the  foliage  is  obscured  by  the  open  flowers. 

Fruit. — Oblate,  regular  at  base,  somewhat  ribbed  at  apex,  irregu- 
larly ribbed  in  cross  section;   sides  commonly  unequal,  color  light 


FIG.  91. — BRANCH  OF  M.  scheideckeri 

(19646)  IN  FLOWER,  APRIL  30 
Young  buds  are  deep  red,  fading  to  nearly 
white  when  fully  expanded.  Bud  clusters  are  in 
close  proximity,  and  the  foliage  is  often  almost 
completely  obscured  by  the  open  flowers. 


orange,  no  bloom.  Skin  smooth,  thin,  tough;  dots  few,  small,  irregular, 
russet,  inconspicuous.  Cavity  shallow,  broad,  obtuse,  regular;  stem 
long,  30  to  40  mm.,  stout,  oblique,  russet,  slightly  pubescent;  basin 
shallow,  broad,  irregular,  ribbed.  Calyx  lobes  in  part  deciduous,  in 
part  persistent;  of  878  fruits  recorded,  331  or  37.7  percent  had  decidu- 
ous calyx  lobes  and  547  or  62.3  percent  had  persistent  lobes.  Core 
large,  cordate,  oblate,  distant,  open;  cells  axile;  carpels  roundish-ovate, 
entire,  glabrous,  moderately  concave.  Seeds  plump,  of  short  thick 
form,  medium  in  size,  medium  brown.  Flesh  greenish  or  yellowish 
according  to  degree  of  maturity,  firm,  crisp,  juicy,  but  becoming 
somewhat  dry  in  overripe  fruits,  acid.  A  fruiting  branch  with  leaves 
mostly  removed  is  shown  in  Fig.  92  from  photograph  taken  September 
16,  1915.  A  further  illustration  to  show  the  concentration  of  fruit  on 
terminal  twigs  within  small  areas,  a  feature  quite  characteristic  of  the 
species,  is  given  in  Fig.  93  from  photograph  taken  October  18,  1916. 


564 


BULLETIN  No.  275 


[June, 


The  species  is  attractive  when  in  flower,  but  its  appearance  in  early 
fall  does  not  commend  it  because  of  a  tendency  to  early  loss  of  both 
foliage  and  fruit. 

M.  scheideckeri  has  been  used  as  the  female  parent  in  19 
crosses  with  12  varieties  and  one  crab  as  pollen  parents.  Four  of  the 
crosses  failed  and  15  are  now  represented  by  154  seedlings  in  orchard 

that  range  in  age  from  7  to  11  years. 
The  total  of  pollinations  was  1,096; 
fruits  matured  260,  or  pollinations 
23.72  percent  successful.  Seed  content 
was  low,  averaging  only  2.16  to  each 
fruit;  about  44  percent  of  the  seeds 
germinated.  Many  seedlings  were  very 
weak  and  over  60  percent  have  died. 
Pollen  from  M.  scheideckeri  was  used 
on  four  varieties,  but  no  seedlings  were 
produced;  three  of  the  crosses  matured 
no  fruits  and  while  the  other  had  fruits 
the  seeds  did  not  germinate.  A  low  de- 
gree of  success  has  attended  the  use  of 
this  species  in  breeding. 

38.  Mains  siberica  frutico  coccinea 
(19643) 

Represented  by  one  tree,  worked  in 
1910,  on  potted  Doucin  stock  which  has 
flowered  and  fruited  abundantly  every 
year  since  1913,  and  three  trees  from 
root-grafts  of  1912.  These  trees,  in  the 
thirteenth  year,  average  13  feet  in 
height,  12  feet  in  spread,  and  4  inches 
in  trunk  diameter.  In  the  early  years 
erect,  becoming  ascending  and  finally 
somewhat  spreading.  The  bark  of  the 
larger  branches  is  light  yellowish- 
brown;  of  twigs  a  still  lighter  brown 
with  a  reddish  tinge. 

Leaves. — When  young  covered  with  a 
fine  close  tomentum  which  is  more 
dense  below  than  above;  mature  leaves 
are  2%  to  4%  inches  long  and  1  to  2 
inches  wide,  elliptical,  oblong  or  ovate, 
or  some  of  the  smaller  lanceolate;  ir- 
regularly doubly  dentate,  acute,  or 


FIG.     92. — BRANCH     OF     M. 

scheideckeri  (19646)  IN 

FRUIT,  SEPTEMBER  16 

This  species  is  attractive 
in  flower  but  tends  to  lose  foli- 
age and  fruit  early. 


19261 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


565 


acuminate,  glabrous  thruout,  dull  dark  green  above,  light  green  or 
grayish  below,  smooth  and  rather  thin.  Petioles  slender,  1  to  1%  inches 
long,  glabrous;  stipules  small,  lanceolate,  entire  or  serrate,  petloled, 
mostly  caducous. 

Flowers. — Borne  from  terminal  and  lateral  buds  of  shoots  of  the 
preceding  year  and  to  some  extent  from  terminal  buds  of  short  spurs 
from  older  wood.  Numbers  of  flowers  to  each  cluster  range,  for  167 
clusters  examined,  from  3  to  9,  with  112  or  67  percent  of  the  clusters 


FIG.  93. — BRANCH  OF  M.  scheideckeri  (19646)  SHOWING 
MASSING  OF  FRUIT  WITHIN  SMALL  AREAS, 
PHOTOGRAPHED  OCTOBER  18 


having  6  flowers  each.  Buds  globular  when  young,  becoming  elongated 
as  they  approach  opening.  Pink,  fading  to  light  pink,  and  finally  to 
pure  white  in  the  open  flower.  Flowers  expand  35  to  40  mm.  Pedicels 
slender,  23  to  28  mm.  long,  pubescent,  green.  Ovary  pubescent,  tinged 
purplish-red.  Calyx  lobes  5,  narrowly  long-triangular,  acuminate, 
pubescent  both  sides,  5  mm.  long,  1.5  mm.  wide  at  base.  Petals  5,  uni- 
form, ovate,  truncate  at  tips,  abruptly  contracted  at  base,  17  to  19  mm. 
long,  9  to  13  mm.  wide,  with  claw,  2  mm.  long.  Stamens  vary  from  18 
to  20,  filaments  slender,  4  to  10  mm.  long,  anthers  plump,  light  yellow. 
Styles  5,  slender,  9  to  12  mm.  long,  connate  %  the  length,  hairy  only 
in  a  narrow  band  about  the  point  of  separation;  tips  of  styles  some- 
what flattened,  stigmas  oval,  capitate.  The  flowers  are  very  fragrant. 
Fig.  94  shows  a  flowering  twig  of  a  dwarf  tree  as  photographed  in  the 
greenhouse  March  12,  1913. 


566 


BULLETIN  No.  275 


[June, 


Fruit. — Roundish  oblate,  average  weight  and  measurements  as 
determined  from  83  fruits  are  as  follows:  weight  4.06  grams,  longitud- 
inal diameter  16  mm.,  transverse  diameter  20  mm.,  regular  at  base, 
apex  more  or  less  irregular,  cross-section  somewhat  ribbed,  ground 
color  yellow,  blushed  with  shades  of  red  from  light  to  medium;  fre- 


FIG.  94. — TWIG  OP  M.  siberica  frutico  coccinea   (19643)   IN 
FLOWER,  MARCH  12.     FIG.  95. — TWIG  IN  FRUIT, 

SEPTEMBER  2 

The  flowering  twig  shown  here  is  from  a  dwarf  tree  in  the 
greenhouse.  When  in  fruit,  this  species  closely  resembles  M. 
baccata  maxima  (810) ;  the  two  are  so  alike  in  all  essential  char- 
acters that  they  are  thought  to  be  identical. 


quently  the  red  spreads  over  the  entire  fruit;  bloom  scant,  waxy, 
white;  skin  smooth,  polished,  thin,  tough;  dots  many,  of  medium  size, 
russet,  conspicuous.  Cavity  deep,  rather  broad,  acute,  regular;  stem 
medium  in  length,  18  to  28  mm.,  stout,  clavate,  erect,  green,  glabrous. 
Calyx  lobes  deciduous  in  all  fruits.  Core  small,  oblate,  nearly  sessile, 
closed;  cells  axile,  uniform;  carpels  obovate,  entire,  glabrous.  Seeds 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  567 

plump,  of  medium  size,  dark  brown;  flesh  yellowish,  firm,  rather  dry, 
acid.  A  small  twig  in  fruit,  from  a  top-graft,  as  photographed  Septem- 
ber 2,  1915,  is  shown  in  Fig.  95.  There  is  only  one  other  form  of  Malus 
in  the  collection  that  closely  resembles  this  and  that  is  No.  810,  M. 
baccata  maxima;  indeed,  the  resemblance  is  so  close  in  all  essential 
characters  that  the  two  are  thought  to  be  identical. 

Used  as  female  in  eighteen  crosses,  one  of  which,  by  Oliver,  failed. 
The  seventeen  crosses  maturing  fruits  had  eight  varieties  and  four 
crabs  as  pollen  parents.  Total  pollinations  680;  fruits  193  or  28.38 
percent  of  the  pollinations  successful.  Seed  content  averaged  6.7  to 
each  fruit  and  64.76  percent  of  the  seeds  germinated.  The  seventeen 
crosses  are  represented  by  536  seedlings  in  orchard  which  range  in  age 
from  six  to  eleven  years.  Performance  of  this  form  of  Malus  when 
used  as  female  parent  may  be  rated  as  good.  As  the  pollen  parent  a 
much  lower  degree  of  success  was  attained.  Pollen  was  used  on  thir- 
teen varieties  and  two  crabs  in  sixteen  crosses  with  438  pollinations 
which  matured  42  fruits  in  five  crosses;  eleven  crosses  failed.  The  42 
fruits  had  the  high  seed  average  of  7.71  to  each  fruit  and  65.43  percent 
of  the  seeds  germinated.  There  are  now  in  orchard  89  seedlings  repre- 
senting progeny  of  these  five  crosses. 

39.  Malus  soulardi  (Bailey)  Britton  (846,19665) 

Pyrus  soulardi  Bailey,  L.  H.  Amer.  Gard.  12,  472.    1891. 
Malus  soulardi  Britton  and  Brown.    Illus.  Fl.  2,  235.    1897. 
Pyrus  ioensis  X  Pyrus  malus  Bailey,  L.  H.    Evolution  of  Our  Native  Fruits, 
189.    1898. 

Scions  received  from  the  U.  S.  Department  of  Agriculture  in  Jan- 
uary, 1907,  under  the  number  19665,  and  a  second  lot  direct  from  the 
Arnold  Arboretum  in  January,  1908,  which  was  carried  as  846.  The 
representation  includes  grafts  on  paradise  and  Doucin  stocks  in  the 
greenhouse,  and  root-  and  top-grafts  in  the  orchard  from  both  lots.  An 
average  root-graft  of  1908  measures  21  feet  high,  20  feet  9  inches 
spread,  and  7.3  inches  trunk  diameter.  Trees  vigorous,  of  symmetrical, 
somewhat  spreading  habit;  bark  of  the  trunks  of  young  trees  dark 
gray,  in  older  trees  becoming  rough;  the  outer  layers  break  up  into 
more  or  less  irregular  longitudinal  ridges  and  assume  a  dark,  brown- 
ish-black color.  Branches  are  dark  gray;  twigs  a  dark  chocolate- 
brown,  or  on  vigorous  non-flowering  twigs  a  deep  reddish-brown. 
Young  twigs  are  covered  with  a  close,  dense  pubescence  which  per- 
sists until  late  fall,  but  mostly  disappears  during  the  first  winter. 
Scions  inserted  on  Virginia  Crab  March  25,  1911,  appeared  as  in  Fig. 
96  when  photographed  October  25  of  the  same  year. 

Leaves. — Large,  thick,  mostly  ovate  and  cordate,  but  sometimes 
rounded  at  base,  oblong,  oval  or  even  obovate,  3  to  5  inches  long,  1% 


568 


BULLETIN  No.  275 


[June, 


to  3  inches  wide,  irregularly  crenate-dentate,  often  distinctly  3-lobed, 
sometimes  variously  notched  towards  the  apex  which  is  usually  ob- 
tusely rounded,  but  occasionally  acute  in  oblong  leaves;  extremely  rug- 
ose, so  marked  is  this  character 
that  the  leaves  are  not  to  be  mis- 
taken for  those  of  any  other 
Malus  in  the  collection,  pubes- 
cent above  and  densely  white 
tomentose  below  when  young,  be- 
coming glabrous  above  but  retain- 
ing the  white  tomentum  thru  the 
season;  very  dark  green  above, 
white  below.  Petioles  stout,  %  to 
1%  inches  long,  persistently  pu- 
bescent; stipules  minute,  linear, 
caducous.  In  examining  leaves  of 
this  species  October  29,  1914,  it 
was  noted  that  the  leaves  were 
dark  green,  showing  no  effects  of 
frost,  while  leaves  on  trees  of  most 
other  species  were  crisp,  brittle, 
and  discolored  from  freezing. 

Flowers. — Flower  clusters  ap- 
pear from  the  terminal  and  lateral 
buds  on  terminal  shoots  and  from 
terminal  buds  of  short  spurs.  On 
most  terminal  shoots  only  the  ter- 
minal buds  produce  flowers,  but 
on  some  there  are  a  few  clusters 
from  lateral  buds,  mostly  near  the 
ends  of  the  shoots.  Flower  buds 
are  of  medium  size,  globular  or 
oval,  deep  pink,  becoming  much 
lighter  as  they  approach  anthesis; 
open  flowers  expand  from  30  to  35 
mm.  and  are  only  slightly  tinged 
with  pink.  Of  25  clusters  exam- 
ined 3  had  4  buds  each,  15  had  5 

each,  6  had  6  each,  and  one  had  7.  Pedicels  are  short  and  stout,  15  to  17 
mm.  in  length,  heavily  pubescent  as  is  also  the  ovary.  Calyx  lobes  5, 
short  triangular,  acute,  pubescent  both  sides.  Petals  5,  almost  orbicu- 
lar, deeply  cordate  at  base,  15  mm.  long,  14  mm.  wide,  with  claw  2 
mm.  in  length;  the  petals  are  imbricated  to  the  base,  presenting  an 
unbroken  ring  about  the  essential  organs,  giving  the  flower  an  appear- 


FIG. 


OF 


96.— TOP-WORKED    TREE 

M.  soulardi  (846) 

Scions  inserted  on  Virginia  Crab 
March  25,  1911,  and  photographed 
October  25  of  the  same  year. 


1926] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


569 


ance  in  strong  contrast  with  the  very  open  flower  of  M .  ioensis.  Sta- 
mens 14  to  21  averaging  about  20,  filaments  slender,  5  to  8  mm.  long; 
anthers  plump,  light  yellow.  Styles  5,  stout,  11  mm.  long,  connate  % 
the  length,  hairy  from  base  nearly  to  the  top.  Stigmas  oval,  terminal. 


FIG.  97. — BUD  CLUSTER  OF  M.  soulardi  (846), 

MARCH  15 

The  petals  lap  over  each  other  at  the  base,  forming 
an  unbroken  ring  about  the  essential  organs.  This  gives 
the  flower  an  appearance  which  contrasts  decidedly  with 
the  very  open  flower  of  M.  ioensis. 


A  bud  cluster  of  this  species  as  photographed  in  the  greenhouse  March 
15,  1916,  is  shown  in  Fig.  97. 

Fruit. — Large  size  for  a  crab,  but  extremely  variable  on  old  trees, 
larger  and  more  uniform  on  young  trees;  one  of  the  trees  from  root- 
grafts  made  in  1908  bore  a  fruit  in  1914  that  weighed  75  grams,  had  a 
vertical  diameter  of  45  mm.,  and  a  transverse  diameter  of  60  mm. 
The  average  of  425  fruits  from  a  tree  twenty  years  old  weighed  38.27 
grams,  had  a  vertical  diameter  of  34  mm.,  and  a  transverse  diameter 
of  41  mm.  The  extreme  range  in  weight  for  the  425  fruits  was  from 
15  grams  for  the  smallest  to  63  grams  for  the  largest.  Form  oblate, 
usually  regular  at  base,  but  quite  irregular  at  apex  and  the  cross- 
section  is  usually  more  or  less  ribbed;  sides  often  unequal;  color  green, 
sometimes  becoming  yellowish  in  the  sun,  and  finally  pale  yellow  when 
thoroly  ripened.  Skin  smooth,  extremely  unctuous,  of  medium  thick- 


570  BULLETIN  No.  275  [June, 

ness,  tough;  dots  numerous,  small,  regular,  dark  green,  inconspicuous. 
Cavity  shallow,  narrow,  obtuse,  often  somewhat  irregular  or  slightly 
lipped;  stem  stout,  22  to  26  mm.  in  length,  clavate,  oblique,  green, 
pubescent;  calyx  of  medium  size,  densely  pubescent,  closed.  Basin 
shallow  to  medium  in  depth,  obtuse,  irregular,  ribbed;  calyx  lobes  of 
medium  size,  short  and  broad,  obtuse,  inflexed;  calyx  tube  long,  large, 
cylindrical,  with  a  stout  projecting  pistil  point.  Core  small,  round, 
median,  closed.  Stamens  marginal,  core  lines  clasping;  carpels  round- 
ish, emarginate,  glabrous,  moderately  concave. 

Seeds  plump,  of  medium  size,  acutely  pointed,  dark  brown.  Flesh 
white,  firm,  crisp,  juicy,  very  acid,  inedible  in  the  raw  state.  The  fruit 
possesses  a  distinct  quince-like  odor  quite  similar  to  that  of  fruit  of 
M.  ioensis.  The  425  fruits  examined  have  an  average  seed  produc- 
tion of  3.18;  this  is  considerably  below  the  average  of  4.22  for  the  crab 
group  and  places  the  species  7th  from  the  bottom  of  the  list  of  25 
species  and  varieties  examined.  At  the  left  of  Fig.  98  is  shown  a 
fruit  of  M.  soulardi  for  contrast  with  the  Hyslop  Crab,  center,  and 
833  M.  mains  ft.  pi.  on  the  right,  all  natural  size. 

In  1891  this  crab  was  described  by  Professor  Bailey  as  Pyrus 
soulardi,  a  new  species.1  Later  Professor  Bailey2  expressed  the  belief 
that  the  Soulardi  crab  was  a  hybrid  between  Malus  ioensis  and  the 
common  apple. 

The  crab  was  first  propagated  and  disseminated  by  J.  G.  Soulard 
of  Galena,  Illinois.  Mr.  Soulard's  statement  places  the  origin  of  the 
tree  as  from  a  crab  thicket  a  few  miles  out  of  St.  Louis.  In  the  years 
following  its  introduction  many  statements  favorable  and  unfavorable 
were  made  with  regard  to  its  qualities,  but  the  fact  that  over  fifty 
years  have  elapsed  since  its  introduction  without  giving  this  crab 
standing  among  desirable  kinds  indicates  general  belief  in  its  worth- 
lessness.  As  a  means  of  throwing  light  upon  its  supposed  hybrid  char- 
acter it  is  desirable  that  seedlings  from  self-fertilized  seed  be  grown  to 
fruiting,  but  the  possibility  of  accomplishing  this  seems  remote  be- 
cause all  efforts  thus  far  made  to  self-fertilize  the  flowers  have  failed. 
M.  soulardi  has  been  used  as  the  female  parent  in  26  crosses;  16 
crosses  failed  and  10  matured  52  fruits;  of  the  575  pollinations  only  9 
percent  were  successful.  The  seed  average  was  2.32  to  each  fruit;  this 
falls  below  the  average  found  for  425  open-pollinated  fruits,  which 
was  3.18  to  each  fruit.  From  the  52  fruits  there  were  121  seeds,  67  or 
55.45  percent  of  which  germinated.  Fifty-four  seedlings  from  7 
crosses  were  planted  in  nursery,  but  only  13  from  4  crosses  are  living 
in  the  seventh  and  eighth  years.  M.  soulardi  was  used  as  the  male 
parent  in  3  crosses,  but  all  failed. 


"Bailey,  L.  H.    Amer.  Card.    12,  472.    1891. 

'Bailey,  L.  H.    Evolution  of  Our  Native  Fruits.    1898. 


19261 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


571 


572 


BULLETIN  No.  275 


[June, 


Self-pollinations  were  attempted  on  193  flowers  in  six  different 
years,  but  no  fruits  matured.  The  species  is  apparently  self-sterile; 
it  fails  entirely  as  a  male  parent  and,  as  a  female  parent,  gives  so  low 
a  percentage  of  successful  pollinations,  has  such  low  seed  content,  and 

produces  seedlings  so  lacking  in 
vitality,  that  it  can  only  be  re- 
garded as  worthless  for  breeding 
purposes. 

40.  Mains  spectabilis  Ait.  Hort. 
Kew.  2,  175.    1810 

This  species  is  believed  to  have 
come  from  China.  It  is  known 
only  in  the  cultivated  condition 
and  appears  under  various  forms, 
some  of  which  have  been  given 
varietal  names.  Flower  colors  are 
variously  stated  to  be  flesh-col- 
ored, dark  red,  rose-red,  pink,  and 
pink  and  white.  It  is  frequently 
mentioned  by  horticultural  writers 
and  has  been  highly  commended 
for  its  beauty.  Scions  of  two 
forms  of  Mains  spectabilis  were 
received  from  the  Arnold  Arbore- 
tum in  1908  and  appear  in  the 
Station  list  as  Nos.  848  and  849. 

Mains  spectabilis  var.  1615 
(848) 

This  form  was  propagated  by 
both  root-  and  top-grafts.  It  is 
now  represented  in  the  collection 
by  two  trees  root-grafted  in  1912 
and  by  one  tree  top-worked  on 
Grimes  in  the  same  year.  The  best 
of  the  two  root-grafted  trees  is 
now  10  feet  high,  has  a  spread  of 
7  feet,  and  a  diameter  of  3.1 
inches.  The  top-worked  tree  is  of 
about  the  same  size  and  has 
formed  a  symmetrical  crown.  This 
in  1908  and  photographed  October 


FIG.  99.— TREE  OF  M.  spectabilis  (848) 

Top-worked  on  Virginia  Crab  in 
1908  and  photographed  October  25, 
1911.  The  habit  of  this  form  of  M. 
spectabilis  seems  to  be  upright,  with 
a  tendency  to  spread  above  as  the 
tree  gets  older. 


form,  top-worked  on  Virginia  Crab 
25,  1911,  is  shown  in  Fig.  99. 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  573 

The  habit  of  this  form  of  M.  spectabilis  appears  to  be  upright 
with  a  tendency  to  spread  above  as  the  tree  gets  older.  Bark  of  large 
branches  is  bright  reddish-brown,  the  twigs  a  darker  shade. 

Leaves. — Oblong-ovate  or  elliptical,  occasionally  obovate  and 
some  smaller  leaves  approaching  lanceolate;  mostly  obtusely  tapered 
at  base,  apex  acute;  finely  crenate,  or  crenate  below  and  obtusely  ser- 
rate above,  slightly  pubescent  when  young,  becoming  glabrous  thruout, 
2  to  4%  inches  long,  %  inch  to  1%  inches  wide,  thin  and  delicate 
when  young,-  becoming  thicker  and  somewhat  coriaceous  at  maturity. 

Flowers. — Produced  from  terminal  and  lateral  buds  of  shoots  of 
the  preceding  year  and  from  terminal  buds  of  short  spurs.  Buds  globu- 
lar, pink,  appearing  much  like  those  of  varieties  of  M.  mains;  flower 
expands  47  mm.,  pedicels  rather  stout,  varying  in  length  from  17 
to  30  mm.,  pubescent,  ovary  heavily  pubescent.  Calyx  lobes  5, 
thick,  broadly  triangular,  acute,  7  mm.  long,  5  mm.  wide  at  base, 
reflexed  in  open  flowers,  pubescent  both  sides.  Petals  oval,  18  mm. 
long,  15  mm.  wide,  with  claw  4  mm.  long,  somewhat  tinged  with  pink. 
Stamens  18  to  20,  filaments  slender,  9  mm.  long;  anthers  plump,  light 
yellow.  Styles  5,  slender,  11  mm.  long,  connate  from  base  up  for  3  to 
4  mm.,  hairy  from  base  to  above  the  point  of  separation;  stigmas  oval, 
capitate,  convex. 

Fruit. — Oblate,  more  or  less  irregular  at  base  and  apex,  in  cross- 
section  ribbed,  sides  unequal,  yellow,  more  or  less  blushed  with  light 
red;  skin  smooth,  thin,  tough;  dots  many,  small,  round,  white,  incon- 
spicuous; cavity  shallow,  of  medium  width,  obtuse,  irregular;  stem  of 
medium  length,  20  to  25  mm.  long,  slender,  erect,  green,  often  tinged 
with  red,  glabrous.  As  to  size,  the  fruits  of  this  variety  fall  into  the 
group  of  crabs  having  fruits  of  medium  size.  Weight  as  averaged 
from  100  fruits  is  4.32  grams.  The  average  longitudinal  diameter  is 
18  mm.,  the  average  transverse  diameter  22  mm.  Calyx  lobes  are 
mostly  persistent;  of  the  100  fruits  examined  the  lobes  were  persistent, 
with  more  or  less  fleshy  bases,  in  91  and  deciduous  in  9.  Basin  shal- 
low or  often  none,  narrow,  obtuse,  irregular,  ribbed.  Core,  when  nor- 
mal, of  medium  size,  oblate,  median,  closed:  commonly  the  core  is  not 
normal,  but  has  a  complete,  or  more  often  partial  secondary  whorl  of 
carpels  superposed  upon  the  normal  whorl ;  carpels  of  the  lower  whorl 
vary  from  5  to  8,  in  the  superposed  whorl  there  may  be  from  1  to  6. 
The  100  fruits  examined  had  numbers  of  carpels  as  follows: 

With  5  carpels 13 

With  6  carpels 51 

With  7  carpels 25 

Writh  8  carpels 8 

With  9  carpels 1 

With  11  carpels 1 

With  12  carpels 1 


574 


BULLETIN  No.  275 


[June, 


The  carpels  of  the  superposed  whorl  are  responsible  for  the  irregulari- 
ties observed  in  many  fruits;  in  some  cases  development  of  seeds  in 
one  or  two  of  the  superposed  carpels  causes  a  protuberance  which 
forces  the  calyx  far  over  to  one  side,  giving  the  appearance  as  shown 
in  the  central  fruit  in  Fig.  73,  page  541.  Cells  are  commonly  abaxile; 
carpels  ovate,  emarginate,  glabrous;  stamens  marginal,  core  lines 


FIG.  100. — FRUITS  OF  M.  spectabilis  (848),  Natural  Size,  SEPTEMBER  11 

Due  to  the  additions  made  by  the  superposed  carpels,  this 
species  has  an  average  seed  production  of  5.31  for  100  fruits,  which 
is  considerably  above  the  average  for  the  crab  group. 


clasping;  seeds  plump,  of  medium  size,  medium  brown;  the  average 
seed  production  for  the  100  fruits  is  5.31,  which  is  considerably  above 
the  average  for  the  crab  group.  This  higher  seed  production  is  due  to 
the  additions  made  by  the  superposed  carpels,  for  these  produce  as 
good  seeds  and  with  almost  as  much  regularity  as  do  the  carpels  of  the 
normal  whorl.  Flesh  yellowish,  firm,  crisp,  juicy,  acid.  A  group  of 
average  fruits  of  this  variety,  photographed  September  11,  1916,  ap- 
pear in  Fig.  100. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  575 

41.  Mains  spectabilis  var.  458/4  (849) 

This  form  is  now  represented  only  by  a  graft  on  potted  paradise 
made  in  1910.  It  flowered  and  was  used  in  breeding  in  each  of  the 
years  1913,  1914,  1916,  and  1917.  Its  appearance  as  photographed 
June  21,  1916,  when  carrying  8  hand-pollinated  fruits,  is  shown  in  Fig. 
101.  Bark  of  the  stem  grayish-brown,  of  the  twigs  reddish-brown, 
smooth,  habit  of  growth  erect. 

Leaves. — Ovate  to  elliptical,  in  general  somewhat  larger  than  are 
the  leaves  of  No.  848,  previously  described;  serrate,  acuminate,  or 
acute,  slightly  pubescent,  becoming  glabrous. 

Flowers. — Produced  from  terminal  and  lateral  buds  of  terminal 
shoots  and  from  terminal  buds  of  rather  numerous  short  spurs,  2  to  17 
flowers  to  the  cluster;  distribution  in  30  clusters  examined  was  as  fol- 
lows: 

Buds  to  the  cluster 2    34567 

Number  of  clusters 1    5    5    11    6    2 

Buds  globular,  pink;  pedicels  rather  stout,  22  to  33  mm.  long,  pubes- 
cent, green.  A  bud  cluster  as  photographed  in  greenhouse  February  24, 
1917,  is  shown  in  Fig.  102.  Flower  expands  about  30  mm.,  calyx  short 
triangular,  3  mm.  wide  at  base,  acute.  Petals  often  nearly  orbicular, 
sometimes  obovate,  variable  in  form  and  number;  38  flowers  examined 
have  petals  in  numbers  as  follows:  12  have  15  petals  each,  5  have  18 
each,  6  have  19  each,  3  have  20  each,  4  have  21  each,  and  the  follow- 
ing numbers  of  petals  are  represented  by  one  flower  each,  14,  16,  17, 
22,  23,  25,  26,  and  28.  Stamens  vary  greatly  in  numbers  and  in  length 
of  filaments,  the  longest  filament  found  is  6  mm.  in  length ;  from  this 
they  range  to  less  than  1  mm.,  some  anthers  are  practically  sessile; 
numbers  of  stamens  with  anthers  in  38  flowers  for  which  there  are 
records  are  as  follows: 

Number  of  stamens 25  to  30  31  to  35  36  to  40  41  to  45  46  to  50  51  to  55  56  to  60 

Number  of  flowers 536  7  11  3  3 

In  one  flower,  in  addition  to  40  stamens  with  anthers  are  5  petaloid  sta- 
mens ;  these  occur  in  most  other  flowers  in  numbers  from  1  to  4.  Styles 
slender,  about  12  mm.  long,  usually  much  contorted  and  nearly  as 
variable  in  numbers  as  are  the  stamens;  for  the  38  flowers  of  record, 
distribution  of  numbers  of  styles  is  as  below: 

Number  of  styles 4    5678    91112131415171822243035 

Number  of  flowers 11167611222311111 

The  styles  are  free  to  the  base  and  are  hairy  from  the  base  up  for  half 
the  length;  stigmas  are  small  and  most  of  them,  as  judged  from 
appearance,  are  incapable  of  performing  proper  functions. 


576 


BULLETIN  No.  275 


[June, 


FIG.    101. — DWARF    TREE    OF    M. 
spectabilis  (849)  IN  GREEN- 
HOUSE 

This  form,  which  was  grafted 
on  paradise  in  1910,  was  photo- 
graphed June  21,  1916,  when 
carrying  8  hand-pollinated  fruits. 


petals  and  stamens,   and  not 
part  to  transformation  of  one 


Fruit. — Oblate,  regular  at  base  and 
apex,  somewhat  ribbed  in  transverse 
section,  yellow  blushed  with  light  red, 
of  medium  crab-size.  Sixteen  fruits 
weighed  and  measured  average  8.09 
grams  in  weight,  23  mm.  in  longitudi- 
nal diameter,  and  27  mm.  in  trans- 
verse diameter.  Skin  smooth,  thin, 
tough ;  dots  few,  small,  regular,  round, 
white,  inconspicuous;  cavity  shallow, 
medium  in  width,  obtuse,  regular; 
stem  slender,  variable  in  length,  25  to 
40  mm.  long,  erect,  green,  slightly 
pubescent;  calyx  open,  lobes  glabrous 
outside,  pubescent  within.  Basins  very 
shallow,  medium  in  width,  obtuse,  ir- 
regular, ribbed.  Calyx  lobes  deciduous 
in  some  fruits,  persistent  in  others;  of 
17  fruits  recorded  10  had  lobes  decid- 
uous, 6  had  persistent  lobes,  and  1  re- 
tained 2  lobes  with  fleshy  bases  while 
3  lobes  were  regularly  deciduous.  Core 
oblate,  of  large  diameter  due  to  the 
intrusion  of  cells  above  the  normal 
number.  Sixteen  fruits  of  record  as  to 
cells  have  distribution  as  follows;  2 
have  6  cells  each,  7  have  7  each,  4 
have  8  each,  3  have  9  each;  these  su- 
pernumerary cells  are  all  crowded  into 
1  whorl  and  not,  as  in  the  other  vari- 
ety of  spectabilis,  into  2  whorls,  one 
superposed  upon  the  other.  Seeds 
plump,  of  medium  size,  dark  brown. 
Flesh  yellowish,  tender,  crisp,  juicy, 
becoming  dry  and  mealy  when  over- 
ripe, subacid.  Three  fruits,  one  with 
persistent  calyx  lobes  and  one  show- 
ing the  scar  of  deciduous  lobes,  are 
represented  natural  size  as  photo- 
graphed June  29,  1916,  in  Fig.  103. 
Multiplication  of  parts  of  the  flowers 
in  this  variety  appears  to  be  due  to 
the  growth  of  adventitious  whorls  of 
wholly  or  even  in  any  considerable 
organ  into  another.  That  there  may 


1926} 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


577 


be  some  transformation  of  stamens  into  petals  is  indicated  by  the 
presence  of  petaloid  stamens  in  most  flowers,  but  where  transformation 
is  an  important  factor  in  the  multiplication  of  petals,  there  is,  usually, 
a-  corresponding  diminution  in  numbers  of  stamens.  In  this  plant  the 
stamens,  instead  of  being  diminished  in  number  by  multiplication  of 
petals,  are  increased  in  numbers  to  almost  as  great  an  extent  as  are  the 
petals.  Not  only  are  petals  and  stamens  involved  in  the  multiplication, 


FIG.  102. — BUD  CLUSTER  FROM  TREE  OF  M. 

spectabilis  (849)  IN  GREENHOUSE, 

FEBRUARY  24 


but  the  styles  also  have  increased  far  beyond  the  expected  numbers. 
Normally  each  style  of  an  apple  flower  represents  a  carpel,  but  in  a 
number  of  flowers  examined  the  styles  far  exceed  the  carpels  in  num- 
bers. Flowers  having  5,  7,  or  8  styles  have  corresponding  numbers  of 
carpels,  but  in  those  flowers  with  from  13  to  35  styles  no  accompany- 
ing carpels  are  apparent;  they  are  either  so  little  developed  as  to  be 
undiscoverable  by  ordinary  means  of  macroscopic  examination,  or  they 
do  not  exist  and,  in  that  case,  the  reasonable  explanation  seems  to  be 
that  the  styles  of  discovered  carpels  have  increased  by  branching.  If 
branching  has  occurred  it  takes  place  below  the  apparent  base  from 
which  the  perfectly  free  styles  spring.  The  contorted,  slender,  and 
weak  appearance  of  the  styles  in  this  variety  suggest  probable  ster- 
ility, but  pollinations  made  have  yielded  some  fruits,  demonstrating 
that  the  variety  is  not  wholly  sterile.  For  the  four  seasons  in  which 
the  variety  has  flowered  114  flowers  have  been  pollinated  with  pollen 


578 


BULLETIN  No.  275 


[June, 


from  twelve  other  varieties.  Seventeen  fruits  were  developed;  this  is 
14.91  percent  of  the  flowers  pollinated,  but  one  of  the  fruits  proved  to 
be  parthenocarpic,  leaving  16  fruits  that  produced  apparently  good 
seeds;  this  represents  as  high  a  percentage  of  successful  pollinations  as 


FIG.  103. — FRUITS  OF  M.  spectabilis  (849), 

NATURAL  SIZE,  JUNE  29 

The  bottom  fruit  shows  persistent  calyx  lobes,  and 
the  one  at  the  left  the  scar  of  deciduous  lobes. 


has  been  obtained,  in  some  cases,  from  species  or  varieties  having  per- 
fectly normal  flowers.  The  16  fruits  produced  seeds  in  numbers  from  2 
to  16  and  the  total  reached  113  or  an  average  of  7  seeds  to  each  fruit, 
nearly  double  the  average  for  all  of  the  crab  group  included  in  the 
Station  records.  From  26  seeds  of  fruits  of  1914,  seven  trees  now  in 
their  tenth  year,  which  were  planted  in  orchard  in  the  spring  of 
1917,  have  been  grown;  of  the  87  seeds  from  fruits  of  1916,  26,  or 
nearly  30  percent,  germinated  and  15  of  the  seedlings  were  living  in 
the  autumn  of  .1923. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  579 

This  variety  of  spectabilis  is  an  interesting  form  of  Malus  and 
further  studies  of  modifications  of  its  flowers  and  the  behavior  of 
flowers  when  pollinated  will  be  made  as  opportunity  offers. 

42.  Malus  sylvestris  fastigiata  bifera  (820) 

Scions  of  this  form  were  received  in  1908  under  the  name  Malus 
fastigiata  bifera,  and  it  has  been  carried  as  No.  820,  under  this  name. 
The  plant  from  which  the  scions  were  taken  was  received  at  the  Arnold 
Arboretum  in  1888  from  L.  Spath,  Rexdorf,  Berlin,  Germany,  as  Pyrus 
ringo  fastigiata  bifera.  Later  the  name  was  changed  to  Pyrus  mains 
fastigiata  bifera,  and  more  recently  to  Malus  sylvestris  fastigiata  bi- 
fera. Botanical  works  consulted  do  not  mention  the  varietal  name 
fastigiata  as  applied  to  the  apple,  but  the  specific  name  sylvestris  was 
used  by  Tournefort1  in  1700  and  he  cites  its  use  by  other  and  earlier 
writers.  Some  later  botanists  have  used  the  name  sylvestris  to  desig- 
nate species  under  the  genus  Pyrus,  others  have  used  it  as  a  varietal 
name  for  forms  of  the  common  apple.  Pyrus  sylvestris  as  used  by 
European  botanists  is  applied  to  the  Smooth  Wild  Apple  of  Europe 
which  they  desire  to  separate  from  Pyrus  malus  or  Malus  malus  be- 
cause of  its  generally  shorter  and  less  pubescent  leaves.  The  "Index 
Kewensis"  does  not  recognize  sylvestris  as  a  species  and  most  botanists 
agree  that  the  plant  called  sylvestris  is  only  one  of  several  forms 
that  are  doubtfully  distinct  from  the  common  apple.  Pyrus  sylvestris 
is  recognized  by  Koch,2  but  he  rates  it  as  very  near  Pyrus  pumila, 
often  closely  resembling  Pyrus  prunifolia,  and  suggests  that  it  is 
only  a  wild  form  of  the  smooth-fruiting  summer  apple  which  came 
thru  cultivation,  from  Pyrus  prunifolia.  All  authorities  agree  that 
the  forms  of  the  wild  European  apples  are  very  numerous  and  that 
to  trace  the  genesis  of  any  particular  form  is  impossible  because 
intermingling,  which  is  very  common  within  the  genus,  has  been 
going  on  for  so  long  a  period  that  original  types  are  obliterated. 
The  course  of  descent  of  existing  forms  is  unknown  and,  altho  the 
extremes  of  variation  are  wide  apart,  characters  that  are  distinctive 
and  of  sufficient  stability  to  be  acceptable  as  means  of  defining  species 
are  wanting.  The  form  in  hand,  Malus  sylvestris  fastigiata  bifera,  is 
one  of  the  European  forms  cultivated  to  some  extent  as  an  ornamental. 

This  species  is  represented  by  two  trees  from  root-grafts  of  1908 
and  one  grafted  in  1914.  Also  by  two  dwarf  trees  in  greenhouse,  one 
grafted  on  Doucin  in  1910,  and  one  on  paradise  in  1917.  The  grafts  of 
1908,  now  sixteen  years  old,  average  12  feet  in  height,  8  feet  in  spread, 
and  with  trunk  diameter  of  3.8  inches.  They  flower  regularly  and 
usually  abundantly. 


Tournefort,  J.  P.    Inst.  Rei  Herb.  1,  634.    1700. 
2Koch,  Karl.    Dendrol.  1,  206.    1869. 


580  BULLETIN  No.  275  [June, 

The  bark  of  the  trunk  and  larger  branches  is  bright,  light  yellow- 
ish-brown, and  smooth  except  where  slightly  roughened  by  the  numer- 
ous transversely  elongated  lenticels.  Twigs  are  bright  reddish-brown 
and  as  late  as  the  middle  of  October  still  show  traces  of  the  fine  white 
pubescence  with  which  they  are  thickly  covered  in  early  spring. 

Leaves. — Elliptical  or  some  of  the  smaller  ovate,  2  to  4%  inches 
long,  %  to  1%  inches  wide,  serrate,  acute,  or  acuminate;  petioles  slen- 
der, %  to  nearly  2  inches  in  length,  pubescent,  narrowly  and  deeply 
channelled.  When  young  the  leaves  are  densely  covered  below  with  fine 
white  tomentum,  scantily  pubescent  above,  becoming  glabrous,  but 
retaining  some  of  the  tomentum  below  until  late  fall.  In  texture  the 
leaves  are  comparable  to  those  of  many  varieties  of  M.  mains. 

Flowers. — Produced  from  terminal  and  lateral  buds  on  terminal 
shoots.  Pedicels  slender,  in  buds,  very  short  so  that  bud  clusters  are 
obscured  by  leaves.  As  development  proceeds  the  pedicels  elongate, 
becoming  nearly  an  inch  in  length;  the  bud  axis  also  elongates  some- 
what, becoming  from  7  to  12  mm.  in  length.  The  buds  are  thus  pro- 
jected outward  so  that  when  fully  open,  leaves  are  completely  hidden 
and  there  is  the  appearance  of  a  solid  mass  of  flowers.  The  number  of 
buds  to  the  cluster  varies  from  2  to  9;  the  distribution  in  98  clusters 
counted  is  as  follows: 

Number  of  buds 2    34      5      6      789 

Number  of  clusters 1     6     15    25    36     11     2    2 

Open  flowers  expand  38  to  40  mm.  In  bud  the  petals  are  deep  reddish- 
pink,  fading  to  nearly  white  in  open  flowers.  Pedicels,  ovary,  and 
calyx  lobes  densely  white  tomentose.  Calyx  lobes  5,  triangular  acute, 
5  mm.  long  by  2%  mm.  wide  at  base,  erect  in  bud,  becoming  reflexed 
in  open  flowers.  Petals  20  mm.  long,  12  mm.  wide,  oblong  or  oval  with 
short  claw.  Stamens  have  slender  filaments  5  to  9  mm.  in  length,  and 
light  yellow  anthers.  In  number  they  vary  extremely ;  thus  the  distrib- 
ution for  39  flowers  examined  is  as  follows: 

Number  of  stamens 5    6789    1012161718192022 

Number  of  flowers 1     1     2     7    5    4    2    2    3    8     1     2     1=39 

Distribution  of  styles  in  these  flowers  is  as  follows: 

With  3  styles 3 

With  4  styles 18 

With  5  styles 18 

Styles  are  stout,  8  to  9  mm.  in  length,  connate  %  the  length  and  hairy 
from  base  to  point  of  separation.  The  long  terminal  shoots  each  pre- 
senting a  solid  mass  of  color  6  to  20  inches  in  length  make  the  tree 
extremely  attractive  at  flowering  time.  A  branch  in  flower  is  shown  in 
Fig.  104. 

Fruit. — Roundish-conical,  maturing  early  in  September.  Diam- 
eter and  weight  as  averaged  from  421  apples  are  as  follows;  longitu- 


1926] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


581 


dinal  diameter  2.88  cm.,  transverse  diameter  3  cm.,  weight  13.72  grams. 
A  peculiarity  of  the  fruit  is  the  absence  of  depression  at  the  basin 
end;  the  apex  is  conical,  with  the  surface  more  or  less  abruptly 
rounded  up  to  the  bases  of  the  somewhat 
thickened,  persistent  calyx  lobes;  base 
somewhat  flattened,  cavity  medium  in 
depth,  rather  broad,  obtuse,  regular;  stem 
medium  in  length,  15  to  20  mm.  long, 
slender,  erect,  pubescent.  Color  dull  yel- 
low, on  some  fruits  a  more  or  less  well 
defined  blush  of  pinkish-red.  Dots  few, 
small,  gray,  inconspicuous.  Calyx  lobes 
rather  short,  broad,  acute,  pubescent,  re- 
flexed;  tube  large,  funnel-form.  Core  me- 
dium in  size,  cordate,  median,  closed  or 
sometimes  half-open;  carpels  ovate,  gla- 
brous, deeply  concave,  varying  in  number 
from  3  to  5.  For  the  421  fruits  examined 
32  had  3  carpels  each,  108  had  4  each,  and 
281  had  5  each.  Seeds  average  5.37  to 
each  fruit.  They  are  inclined  to  be  shriv- 
elled somewhat,  are  of  medium  size,  and 
of  medium  brown  color.  Flesh  is  yellow- 
ish, firm,  dry,  becoming  mealy  in  over- 
ripe fruits;  the  flavor  is  mildly  subacid. 
When  ripe  the  skin  cracks  irregularly  over 
the  whole  surface,  giving  a  netted  appear- 
ance to  the  fruit.  A  branch  in  fruit  is 
shown  in  Fig.  105  from  photograph  taken 
August  22,  1917. 

This  form  of  sylvestris  was  used  as  fe- 
male in  seventeen  crosses  by  twelve  vari- 
eties; four  crosses  failed  to  mature  fruit 
and  four  failed  because  seeds  did  not  ger- 
minate; nine  crosses  are  represented  in 
orchard  by  213  seedlings  from  seven  to 
twelve  years  old.  The  number  of  pollina- 
tions made  was  491,  from  which  144  fruits 
matured,  or  29.32  percent  of  the  pollina- 
tions produced  fruits.  As  the  pollen  par- 
ent the  variety  was  used  in  seven  crosses; 

four  crosses  failed  and  three  matured  16  fruits;  only  11.67  percent  of 
the  137  pollinations  were  successful.  The  three  crosses  producing  fruits 
are  represented  in  orchard  by  40  seedlings  ten  and  twelve  years  old. 


Fia.     104. — BRANCH     op     M. 

sylvestris    jastigiata    bifera 

(820)  IN  FLOWER,  APRIL  30 

In  this  species,  the  pedi- 
cels and  bud  axis  elongate  as 
development  proceeds,  pro- 
jecting the  buds  outward. 
When  the  flowers  are  fully 
open,  they  form  a  solid  mass 
completely  hiding  the  leaves. 


682 


BULLETIN  No.  275 


[June, 


FIG.  105. — FRUITS  OF  M.  sylvestris  fastigiata  bifera  (820) 

PHOTOGRAPHED  AUGUST  22,  1917 

These  fruits  are  a  dull  yellow  in  color,  with  sometimes  a  more  or  less 
well-defined  blush  of  pinkish-red.  When  the  fruit  is  ripe,  the  skin  cracks  over 
the  entire  surface,  giving  it  a  netted  appearance. 


Whether  used  as  male  or  female  the  progeny  of  this  form  of  Malus 
is  of  reasonable  vigor  and  the  degree  of  success  in  crossing  encourages 
further  use  in  breeding. 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  583 

43.  Mains  sylvestris  ft.  pi.  (833) 

This  form  was  received  as  Mains  mains  ft.  pi.  and  has  been  prop- 
agated under  the  number  833.  The  original  plant  in  the  Arnold 
Arboretum  was  received  from  a  nursery  more  than  thirty  years  ago  as 
Pyrus  communis;  later  the  name  was  changed  to  Mains  mains  ft.  pi. 
and  finally  to  Mains  sylvestris  ft.  pi.  Of  ten  root-grafts  made  January 
20,  1908,  six  survived  and  were  planted  in  orchard  in  the  spring  of 
1910.  These  trees  have  maintained  a  uniform  growth,  are  fastigiate  in 
form  with  average  dimensions  as  follows;  height  14  feet  9  inches; 
spread  12  feet;  and  trunk  diameter  of  5.4  inches.  Bark  of  trunk  and 
branches  dark  brown  with  a  tinge  of  olive-green ;  twigs  reddish  choco- 
late-brown, pubescent  when  young,  but  becoming  nearly  glabrous  in 
early  fall. 

Leaves. — One  to  4  inches  long,  %  to  2  inches  wide.  The  larger 
leaves  are  few  and  confined  to  the  outer  ends  of  rapidly  growing 
shoots.  Leaves  from  lateral  buds  and  spurs  below  are  mostly  small. 
Large  leaves  are  roundish  ovate,  the  smaller  vary  from  orbicular  to 
oblong  and  lanceolate,  acuminate  or  acute,  crenate-dentate  or  with 
blunt  serrations  toward  the  apex;  densely  clothed  with  close-matted 
tomentum  below,  and  sparsely  pubescent  when  young,  becoming  gla- 
brous above;  petioles  stout,  more  or  less  red  in  color;  stipules  small, 
lanceolate,  persisting  on  some  leaves. 

Flowers. — One  of  the  trees  in  orchard  produced  a  few  flower 
clusters  and  a  few  fruits  in  1915;  in  1916  all  of  them  flowered  sparingly 
and,  tho  not  heavily,  some  of  the  trees  have  flowered  each  year  since. 
Flowers  are  borne  from  terminal  and  lateral  buds  of  terminal  shoots. 
Of  70  clusters  counted,  1  had  4  buds,  10  had  5  each,  41  had  6  each,  and 
18  had  7  each.  In  bud  the  clusters  are  short  and  compact,  pink,  fading 
to  white  as  flowers  expand.  Open  flowers  vary  considerably  in  size; 
those  measured  range  from  30  to  53  mm.  Pedicels  are  rather  stout, 
pubescent,  10  to  16  mm.  long,  ovary  pubescent;  calyx  lobes  triangular 
to  lanceolate,  acute,  pubescent  both  sides,  tips  reflexed  in  open 
flowers.  Petals  nearly  orbicular,  abruptly  contracted  to  the  short  claw, 
varying  in  number  from  5  to  10,  pure  white  when  expanded.  Petaloid 
stamens  2  to  5  of  various  forms.  Stamens  with  anthers  27  to  34,  fila- 
ments slender,  7  to  11  mm.  long,  anthers  plump,  light  yellow,  mostly 
with  abundant  pollen.  Styles  6  to  9,  slender,  11  mm.  long,  connate 
nearly  half  the  length,  hairy  from  base  to  above  the  point  of  separa- 
tion; stigmas  oval,  oblique.  Multiplication  of  petals  is  not  so  uni- 
versal as  might  be  inferred  from  the  designation  ftore  pleno;  as  many 
flowers  have  the  normal  5  as  have  greater  numbers  and  few  possess  a 
complete  second  whorl.  The  flowers,  however,  are  large  and  usually 
the  clusters  are  massed,  conspicuous  and  very  showy. 


584  BULLETIN  No.  275  [June, 

Fruit. — Distinctly  oblate,  with  regular  base,  corrugated  apex,  and 
sides  somewhat  unequal.  The  average  of  14  fruits  gives  the  weight  as 
27  grams,  longitudinal  diameter  31  mm.,  and  transverse  diameter 
40  mm.  The  ground  color  is  yellow  blushed  and  washed  with  an  at- 
tractive red;  bloom  scanty,  waxy,  gray;  skin  smooth,  thin,  tender; 
dots  few,  small,  round,  white  or  russet,  inconspicuous.  Cavity  shallow, 


FIG.   106. — FRUITING  BRANCH  OF   M.  sylvestris 

fl.  pi.  (833),  PHOTOGRAPHED  OCTOBER  2 
Apparently  this  variety  succeeds  better  as  a 
male  parent  than  as  a  female  parent.  Seedlings 
from  this  species  as  a  female  parent  are  small 
and  weak;  when  it  is  used  as  a  male  parent,  the 
seedlings  are  more  vigorous. 


broad,  obtuse;  stem  medium  in  length,  rather  stout,  erect,  smooth, 
calyx  large,  open.  Basin  shallow,  broad,  ribbed,  calyx  lobes  long,  slen- 
der, acute  with  reflexed  tips ;  core  of  medium  size,  oblate,  median,  half 
open;  carpels  obovate,  entire,  tufted,  moderately  concave;  seeds 
plump,  of  medium  size,  flesh  yellowish,  tender,  moderately  juicy,  be- 
coming somewhat  mealy  when  over-ripe,  sweet.  A  fruiting  branch  is 
shown  in  Fig.  106  and  a  single  fruit  appears  at  the  right  in  Fig.  98, 
page  571. 

M.  sylvestris  fl.  pi.  has  been  used  as  female  in  two  crosses,  one  by 
Shockley  in  1916  and  one  by  Fanny  in  1921.  Pollinations  by  Shockley 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  585 

were  less  than  5  percent  successful,  the  seed  average  was  7  to  each 
fruit  and  53  percent  of  the  seeds  germinated;  54  percent  of  the  seed- 
lings are  living  in  the  eighth  year,  but  the  trees  are  small  and  deficient 
in  vigor.  For  the  Fanny  cross,  while  25  percent  of  the  pollinations 
matured  fruits,  seed  content  of  the  fruits  was  low,  only  20  percent 
germinated,  and  the  seedlings  were  small  and  weak.  Degree  of  success 
does  not  encourage  further  use  of  this  plant  as  a  female  parent.  As  a 
male  parent  in  four  crosses,  one  cross  failed  and  three  yielded  33 
fruits.  Seed  content  was  low,  but  germination  was  fair  and  the  seed- 
lings are  more  vigorous  than  were  those  of  the  other  group.  Appar- 
ently the  variety  succeeds  better  as  the  male  parent. 

44.  Mains  sylvestris  (19631) 

Scions  received  from  the  U.  S.  Department  of  Agriculture  in  Jan- 
uary, 1907,  under  the  number  19631,  with  this  notation,  "Sometimes 
called  M .  acerba,  and  by  the  older  botanists  was  considered  a  form,  at 
least,  of  the  common  apple."  Success  did  not  attend  propagation  with 
these  scions.  A  few  started  growth  but  died  before  the  end  of  the 
season.  Scions  received  from  the  Arnold  Arboretum  in  1908  were  suc- 
cessfully worked  and  the  species  is  now  represented  by  three  trees 
from  root-grafts  of  1908  and  by  two  dwarfs,  one  on  paradise,  the  other 
on  Doucin.  These  dwarfs  have  been  forced  in  greenhouse  for  eleven 
years  but  only  in  one  year  (1918)  were  flowers  produced,  and  these  in 
very  few  clusters. 

The  trees  in  orchard,  now  seventeen  years  old,  average  21  feet 
high,  19  feet  in  spread,  and  8.4  inches  in  diameter.  They  are  healthy 
and  vigorous,  but  remarkably  tardy  in  flower  production.  One  tree  in 
1919  and  again  in  1920  bore  a  few  scattered  clusters,  but  none  have 
appeared  since. 

Bark  of  trunk  light  olive-brown,  of  twigs  light  brown,  but  twigs 
are  gray  in  appearance  because  of  the  close  pubescence  which  persists 
thru  the  season. 

Leaves. — Mostly  broadly  ovate  2%  to  3%  inches  long,  1  to  2 
inches  wide,  doubly  serrate,  or  dentate,  shortly  acuminate,  glabrous 
above,  covered  below  with  a  dense,  short  pubescence  which  is  persist- 
ent. Petioles  l/>  to  1  inch  long,  more  or  less  pubescent. 

Flowers. — The  flowers  as  described  from  the  greenhouse  tree  are 
borne  in  clusters  of  6  on  terminal  buds  of  twigs.  Expansion  of  flower 
34  mm.  Calyx  lobes  5,  narrowly  triangular,  acuminate,  strongly  re- 
flexed,  medium  in  size,  pubescent.  Buds  are  large,  oval,  with  round 
apex,  and  color  light  pink.  Pedicel  is  medium  length,  stout,  pubescent, 
erect;  ovary,  pubescent;  petals  are  5  in  number,  oval  to  elliptical,  with 
round  apex;  claw  short  and  broad.  Fourteen  stamens  measure  5  to 
7  mm.  long,  filaments  slender;  anthers  plump,  medium  size,  light  yel- 


586  BULLETIN  No.  275  [June, 

low.    Styles  5,  10  mm.  long,  slender,  connate  for  3  mm.  of  their  length, 
hairy  at  base,  stigma  is  medium  size,  oval,  oblique. 

Fruit. — Roundish-oblate,  with  regular  and  rounded  base,  and  reg- 
ular apex,  regular  cross-section,  and  equal  sides.  Size  small  to  me- 
dium; appears  like  a  small  apple;  typical  fruit  weighs  42  grams. 
Color  is  self  greenish-yellow  or  sometimes  very  faintly  striped.  Bloom 
is  scant,  waxy,  white;  skin  smooth,  tough,  medium  in  thickness.  Dots 
few,  small,  irregular,  greenish,  scattered,  inconspicuous.  Cavity  shal- 
low, medium  broad,  obtuse,  regular,  has  short  slender,  erect,  green, 
glabrous  stem.  Calyx  persistent,  small,  pubescent,  closed.  Basin  shal- 
low, medium  broad,  obtuse,  and  regular.  The  calyx  lobes  are  medium 
size,  short  and  broad,  acute,  erect;  calyx  tube  medium  in  length, 
medium  size,  and  conical.  Core  medium  size,  cordate,  oblate,  median, 
half  open.  Stamens,  marginal,  core-lines  clasping;  cells  slightly  ab- 
axile,  uniform;  carpels,  obovate,  emarginate,  glabrous,  concave.  The 
seeds  are  plump,  medium  size,  and  dark.  Axis  medium  length,  erect; 
flesh  is  greenish,  firm,  crisp,  juicy,  acid,  with  crab-like  flavor.  The 
number  of  seeds  is  high;  of  3  fruits,  one  has  10  perfect  seeds  and  the 
other  2  have  9  each. 

45.  Mains  toringo  Carriere  Rev.  Hort.,  210.     1872 

Pyrus  toringo  sieboldi  Cat.  Rais.    1,  4.    1856.  Koch,  Dendrol.,  212.    1869. 

Regel,  Ind.  Sem.  Hort.  Petrop.,  51.    1858. 
Pyrus  sieboldi  regel  Gartenflora  8,  82.    1859. 

Each  of  the  two  lots  of  Malus  scions  received,  the  one  from  the 
Arnold  Arboretum  thru  the  U.  S.  Department  of  Agriculture  in  1907, 
and  the  one  direct  from  the  Arnold  Arboretum  in  1908,  included  three 
forms  of  this  species:  in  the  earlier  lot  under  the  numbers  19652, 
19654,  and  19664;  in  the  second  lots  as  Malus  toringo,  yellow  fruit, 
Malus  toringo,  red  fruit,  and  Malus  toringo,  dwarf  spreading;  of  the 
last  the  red  fruited  form  was  given  the  number  851,  the  yellow  fruited 
form  the  number  853,  and  the  dwarf  form  became  852.  Scions  of 
19652  and  19654  failed  to  grow  and  were  thus  eliminated.  The  form 
under  19664  proved  to  be  dwarf  and  identical  with  that  under  852. 
There  are  then  three  forms  in  the  collection  which  may  be  described. 

Malus  toringo,  red  fruit  (851) 

Represented  in  the  collection  by  two  trees  from  root-grafts  made 
in  January,  1908,  three  trees  from  root-grafts  of  1914,  one  tree  top- 
worked  on  Grimes,  and  one  tree  from  top-graft  on  potted  Doucin 
stock.  This  last  tree,  forced  each  spring  since  1913,  flowered  in  1914, 
again  in  1916,  and  each  year  since.  The  top-grafted  tree  flowered  for 
the  first  time  in  1916,  as  did  also  three  of  the  trees  from  root-grafts  of 
1908.  Trunks  of  trees  from  12  to  18  inches  in  length,  breaking  into 


1926]  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  587 

several  branches  all  of  which  are  strictly  erect.  Bark  dark  reddish- 
brown,  smooth;  lenticels  conspicuous,  rather  small,  mostly  trans- 
versely elongated,  light  grayish-brown;  twigs  long,  slender,  purplish- 
brown,  glabrous.  All  branches  have  numerous  spurs  which,  on  the 
lower  half  of  the  tree,  are  short,  %  to  1%  inches  long,  while  above 
they  range  from  2  to  3  inches  in  length.  The  largest  of  the  older  trees 
is  22  feet  2  inches  in  height,  has  a  spread  of  19  feet  3  inches,  and  a 
trunk  diameter  of  6.2  inches. 

Leaves. — Leaves  of  flowering  shoots  thin,  of  delicate  texture,  and 
of  various  forms;  lanceolate,  elliptical,  obovate  and  spatulate  are  the 
more  common  shapes;  1  to  2  inches  long,  serrate  or  sometimes  crenate 
or  even  entire  below  and  serrate  towards  the  apex,  acute,  or  obtuse, 
pubescent  both  sides,  glabrate.  Leaves  of  sterile  shoots  mostly  broadly 
ovate  in  outline,  3-lobed,  occasionally  elliptical  or  obovate,  irregularly 
crenate.  The  lobed  leaves  vary  considerably  in  relative  size  of  the 
lobes;  in  most  the  central  lobe  is  much  the  larger,  often  indented 
towards  the  apex  and  itself  appearing  3-lobed;  in  other  leaves  the 
principal  incisions  approach  the  midrib  and  the  lateral  lobes  are  but 
little  smaller  than  the  central;  margins  are,  in  part,  crenate  and,  in 
part,  serrate;  mostly  acute,  glabrous  thruout  when  mature,  1%  to  4 
inches  in  length,  1  to  3  inches  broad,  somewhat  coriaceous.  Petioles 
stout,  y±  to  %  inch  long,  usually  red  as  are  also  the  midribs  below, 
glabrous  or  very  nearly  so.  Stipules  foliaceous,  ovate,  serrate,  or 
variously  incised. 

Flowers,. — This  variety  flowers  from  terminal  and  lateral  buds 
of  terminal  shoots  and  from  terminal  buds  of  the  numerous  short 
spurs.  Numbers  of  flowers  to  the  cluster  for  28  clusters  examined  are 
as  follows:  with  2  flowers  1  cluster,  with  4  flowers  2,  with  5  flowers 
5,  with  6  flowers  18,  and  with  7  flowers  2.  Young  buds  deep  pink,  fad- 
ing before  opening.  In  fading  the  margins  retain  color  longest  giving  the 
buds,  just  before  opening,  a  striped  appearance.  Fully  expanded  petals 
are  nearly  white,  some  retaining  a  slight  pink  tinge  along  the  margins. 
Flowers  expand  20  mm.;  pedicels  slender,  25  to  35  mm.  long,  glabrous, 
as  is  also  the  ovary.  Calyx  lobes  narrowly  triangular,  3  mm.  long, 
1  mm.  wide  at  base,  acuminate,  glabrous  without,  slightly  pubescent 
within,  erect  in  bud,  reflexed  but  little  in  open  flowers.  Petals  5,  oval 
or  oblong,  rounded  at  apex,  10  mm.  long,  6  mm.  wide,  claw  short. 
Stamens  12  to  20,  distributed,  for  76  flowers  examined,  in  numbers  as 
below: 

Number  of  stamens 12  13    14     15     16    17    18    1920 

Number  of  flowers 4    5     11     12     13    6     11     5    9 

Filaments  slender  2  to  5  mm.  long,  anthers  plump,  light  yellow,  pollen 
orange.  Styles  3  to  5;  for  the  76  flowers  there  were  32  with  3  styles 
each,  42  with  4  styles  each,  and  one  with  5  styles;  slender,  6  mm.  long, 


588  BULLETIN  No.  275  [June, 

connate  %  the  length,  glabrous  at  base,  hairy  in  a  ring  above  and 
below  the  point  of  separation.  Stigmas  small,  oval,  capitate. 

Fruit. — Globular,  regular  at  base  and  apex  and  in  cross-section; 
sides  equal,  light  or  sometimes  darker  red,  usually  entirely  covering 
the  yellow  ground  color,  no  bloom.  Skin  smooth,  thin,  tough.  Cavity 
very  small,  narrow,  obtuse,  regular;  stem  rather  long,  18  to  25  mm., 
slender,  erect,  green,  glabrous.  Calyx  lobes  uniformly  deciduous  early 
in  the  development  of  the  fruit.  This  is  one  of  the  smallest  fruits 
represented  in  the  Station  collection;  the  average  of  49  fruits  weighed 
and  measured  is  a  fruit  weighing  .33  gram,  with  a  vertical  diameter 
of  7.7  mm.  and  a  transverse  diameter  of  7.8  mm. ;  there  were  12  fruits 
with  3  carpels  each  and  37  with  4  each;  they  produced  135  seeds,  an 
average  of  2.75  to  each  fruit.  Core  large  in  proportion  to  size  of  the 
fruit,  cordate,  median,  closed.  Core  lines  meeting;  carpels  obovate, 
glabrous,  moderately  concave.  Seeds  small,  plump,  very  light  brown. 
Flesh  yellowish,  firm,  rather  dry,  acid,  and  somewhat  astringent. 

46.  Mains  toringo,  yellow  fruit  (853) 

Except  for  fruit  color  this  is  very  similar  to  851  and  may,  with 
propriety,  follow  that  number.  Represented  by  one  tree  from  root- 
graft  of  1908;  one  from  root-graft  of  1912;  one  top-graft  of  1912  on 
Grimes;  two  trees  from  root-grafts  of  1914,  and  one  tree  grafted  on 
potted  paradise  stock  in  1910  and  fruited  in  the  house  in  1914,  again 
in  1916,  and  in  each  year  since. 

Tree  of  strictly  erect  habit;  the  one  tree  from  root-graft  of  1908 
and  now  seventeen  years  old  has  a  height  of  18  feet  7  inches,  a  spread 
of  15  feet  2  inches,  and  a  trunk  diameter  of  5.7  inches.  Bark  of  trunk 
and  large  branches  dark  brown,  smooth;  twigs  reddish-brown,  some- 
times conspicuously  red;  lenticels  conspicuous,  in  part  round,  in  part 
elongated  transversely,  light  gray.  Twigs  are  in  general  more  slender 
than  are  those  of  851  and  short  spurs  noticeably  less  numerous.  Habit 
of  growth  is  shown  in  Fig.  107,  which  is  reproduced  from  a  photograph 
taken  October  26,  1911,  of  a  tree  top-worked  on  Virginia  Crab  in  the 
spring  of  1908.  This  tree  died  in  1914  from  an  attack  of  blight  follow- 
ing removal  in  1913  to  a  new  orchard. 

Leaves. — Those  of  flowering  twigs  of  slender  form,  mainly  lanceo- 
late, elliptical  or  obovate,  %  to  2  inches  long,  %  to  %  inch  wide, 
finely  serrate,  obtuse  or  acute,  scantily  pubescent  on  both  sides.  Peti- 
oles slender,  %  to  1  inch  long,  pubescent.  Leaves  of  sterile  shoots 
mostly  3-lobed,  sometimes  oblong  or  elliptical,  2  to  4  inches  long,  %  to 
2  inches  broad,  serrate,  acute,  glabrous  thruout.  Petioles  %  to  1% 
inches  long,  slender,  glabrous. 

Flowers. — Produced  profusely  from  terminal  and  lateral  buds  of 
terminal  shoots  and  from  short  branches  or  long  spurs  3  to  8  inches 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


589 


long  that  spring  from  the  larger  branches;  lateral  clusters  on  these 
short  branches  come  from  short  spur-like  processes  %  to  %  inch  long. 
Of  15  clusters  examined,  5  had  4  buds  each,  7  had  5  each,  and  3  had  6 
each.  Buds  red  or  very  deep  pink,  fading  to  nearly  white  before  petals 


FIG.  107. — TOP-WORKED  TREE  OF  M. 
toringo  (853)  FOUR  YEARS 

FROM  GRAFTS 

This  species  is  strictly  erect  in  habit. 
The  tree  illustrated  here  was  top-worked 
on  Virginia  Crab  in  the  spring  of  1908,  and 
was  photographed  October  26,  1911. 


open.  Twigs  in  bud  are  shown  in  Fig.  108.  Fully  open  flowers  are 
either  pure  white  or  occasionally  with  a  faint  tinge  of  pink;  flowers 
expand  23  mm.  Pedicels  slender,  21  to  28  mm.  long,  slightly  pubescent 
as  is  also  the  ovary.  Calyx  lobes  5,  triangular  acuminate,  3  mm.  long, 


590  BULLETIN  No.  275  [June, 

1  mm.  wide  at  base,  glabrous  without,  slightly  pubescent  within,  erect 
in  bud,  reflexed  in  open  flowers.  Petals  5,  oval  or  oblong,  rounded  at 
apex,  12  mm.  long,  8  mm.  wide,  abruptly  contracted  at  base,  claw 


FIG.  108.— TWIGS  OF  M.  toringo  (853)  IN 

BUD  IN  GREENHOUSE,  MARCH  14 
Flowering  is  profuse  from  terminal  and  lat- 
eral buds  of  terminal  shoots  and  from  short 
branches  3  to  8  inches  long  that  spring  from 
the  larger  branches.  On  these  short  branches 
lateral  clusters  appear  on  short  spur-like  pro- 
cesses %  to  y±  inch  long. 

very  short.  Stamens  for  65  flowers  examined  vary  from  8  to  15  with 
distribution  as  below: 

Number  of  stamens 8    9   10    11     12    13  14  15 

Number  of  flowers 1     3    6    24     19    6    4    2 

Filaments  slender,  5  to  7  mm.  long,  anthers  plump,  light  yellow. 
Styles  vary  from  1  to  4 ;  for  the  65  flowers  recorded  the  distribution  is 
as  follows: 

Number  of  styles 1     2     3      4 

Number  of  flowers 4    8    33    20 

Styles  slender,  8  mm.  long;  connate  about  %  the  length,  glabrous  at 
base  and  above,  but  hairy  about  the  point  of  separation.  Stigmas 
small,  round,  capitate. 


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APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


591 


Fruit. — Round  or  sometimes  slightly  oblate,  very  small;  from  30 
fruits  weighed  and  measured  the  average  weight  obtained  is  .21  gram, 
the  average  longitudinal  diameter  6  mm.,  and  the  average  transverse 
diameter  7  mm.  The  distribution  of  carpels  in  these  fruits  is  as  fol- 
lows: 3  fruits  had  3  each,  23  fruits  had  4  each,  and  4  fruits  had  5  each. 
The  total  number  of  seeds  is  107,  an  average  of  3.56  to  each  fruit. 
Fruit  regular  at  base  and  apex,  sides  equal,  orange-yellow,  skin  smooth, 


FIG.  109. — FRUITING  BRANCH  OF  M.  toringo 
(853),  OCTOBER  25 

Fruits  of  this  species  are  very  small;  of  30 
fruits  weighed  and  measured  the  average 
weight  was  21  gram,  average  longitudinal  diam- 
eter 6  mm.,  and  the  average  transverse  diam- 
eter 7  mm. 


thin,  tough,  dots  none;  cavity  very  shallow,  sometimes  scarcejy  appar- 
ent, narrow,  obtuse,  regular;  stem  slender,  varying  between  13  and  23 
mm.  in  length,  glabrous,  erect,  dull  red.  Calyx  lobes  regularly  decidu- 
ous; basin  scarcely  apparent.  The  plane  surface  of  the  truncated  apex 
is  covered  by  the  circular  russet  scar  left  by  the  deciduous  calyx  and 
the  only  depression  is  the  small,  conical  calyx  tube  in  the  center.  Core 
large  in  proportion  to  size  of  fruit,  cordate,  oblate,  median,  half  open; 
carpels  obovate,  entire,  glabrous,  deeply  concave.  Seeds  plump,  small, 
very  light  brown;  flesh  yellowish,  firm,  moderately  juicy,  becoming 


592 


BULLETIN  No.  275 


[June, 


rather  dry  when  fully  ripe,  acid,  and  somewhat  astringent.  A  fruiting 
branch  of  this  form  is  shown  in  Fig.  109. 

-  47.  Mains  toringo  dwarf,  spreading  (852,19664) 
Under  the  number  19664  this  dwarf  form  of  Mains  toringo  is 
represented  by  one  tree  from  root-grafts  of  1917,  one  tree  top-grafted 

in  1913,  two  trees  from  root-grafts 
made  in  1914,  and  one  tree  top- 
worked  on  potted  paradise  for 
forcing  purposes. 

Under  the  number  852  it  is  rep- 
resented by  three  trees  root- 
grafted  in  1914.  The  habit  of 
growth  is  low  and  wide-spreading 
with  numerous  variously  contorted 
branches.  One  of  the  trees  from 
root-graft  made  in  1907  when  ten 
years  old  had  an  extreme  height 
of  6  feet  4  inches,  a  spread  of  9 
feet,  and  a  trunk  diameter  of  3.1 
inches.  As  further  illustration  of 
the  slow  growth  of  this  form  of 
Malus  attention  may  be -called  to 
Fig.  110,  which  shows  the  growth 
for  four  seasons  of  scions  top- 
grafted  in  the  spring  of  1908.  The 
central  vigorous  branches  belong 
to  the  Virginia  Crab  stock;  the 
grafts  are  below.  Bark  of  trunk 
gray,  the  rough  outer  bark  broken 
into  rectangular,  scaly  plates; 
bark  of  branches  dark  brown;  len- 
ticels  numerous,  small,  mostly 
round,  light  cinnamon-brown; 
twigs  reddish-brown,  stout,  gla- 
brous, internodes  short. 

Leaves. — Those  of  flowering 
shoots  very  small  at  flowering 
time  and  even  when  mature  quite 
small,  elliptical  or  lanceolate,  1% 
to  2l/2  inches  long,  %  to  %  inch 
wide,  serrate,  or  irregularly  den- 
tate, sometimes  irregularly  in- 
cised, but  scarcely  lobed,  acute, 


FIG.  110. — TOP-GRAFTS  OF  M.  toringo 

(852),  SHOWING  GROWTH  OF 

FOUR  SEASONS 

The  central  vigorous  branches  be- 
long to  the  Virginia  Crab  stock;  the 
grafts  are  below.  The  growth  of  this 
form  of  Malus  is  slow,  and  the  habit 
of  growth  is  low  and  wide-spreading 
with  numerous  branches  contorted  in 


various  wavs 


19881 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


593 


scantily  pubescent  on  both  sides  when  young,  becoming  glabrous  except 
along  the  midrib  below.  Petioles  slender,  %  to  1  inch  long,  slightly 
pubescent.  Leaves  of  sterile  branches,  broadly  ovate  in  outline,  mostly 
3-lobed,  iy4  to  2%  inches  long,  %  to  1%  inches  wide,  occasionally 
elliptical,  irregularly  coarsely  dentate  or  variously  incised,  acute,  com- 
monly folded  lengthwise  and  the  midrib  curved  outward  and  down- 
ward, glabrous  above,  pubescent  below.  Petioles  short,  %  to  %  inch 
long,  stout,  pubescent,  red,  or  dark  brown;  internodes  are  short  and  the 
folded  curved  leaves  appear  crowded,  particularly  near  the  ends  of  the 
shoots. 


FIG.  111. — TWIGS  OF  M.  toringo  (19664)   IN 

BUD  IN  GREENHOUSE,  MARCH  12 
Buds  are  small,  globular,  and  dark  red.   As 
they  develop,  they  become  elongated  and  fade 
to  light  pink.  The  open  flowers  are  pure  white. 


Flowers. — Produced  from  terminal  and  lateral  buds  of  shoots  and 
spurs;  lateral  clusters  are  either  sessile  or  are  raised  on  very  short 
spur-like  processes.  Numbers  of  flowers  to  the  cluster  vary  between 
1  and  7;  for  194  clusters  examined  the  distribution  is  as  follows: 


Number  of  flowers  to  cluster 1 

Number  of  clusters . .  ....  2 


2 

12 


3 

67 


4 
73 


5 
29 


Buds  small,  globular,  dark  red,  becoming  elongated  and  fading  to  light 
pink.  Fig.  Ill  illustrates  a  branch  (of  19664)  in  bud  as  photographed 
in  the  greenhouse  March  12,  1913.  Flowers  open  pure  white,  expanding 
20  to  23  mm.  Pedicels  slender,  22  to  25  mm.  long,  slightly  pubescent. 


594 


BULLETIN  No.  275 


[June, 


Ovary  glabrous,  more  or  less  tinged  with  red.  Calyx  lobes  broadly  tri- 
angular, obtuse,  3  mm.  long,  1%  mm.  wide,  at  base,  glabrous  without, 
pubescent  within.  Petals  5,  white,  oblong,  or  obovate,  11  mm.  long, 


FIG.  112. — FRUITING  BRANCH  OF  M.  toringo  (19664),  SEPTEMBER  16 
Fruits  are  round  and  very  small;  the  average  weight  of  64 
fruits  was  .25  gram. 


7  mm.  wide,  contracting  abruptly  to  the  short  claw.  Stamens  range  in 
number  from  7  to  21,  as  appears  from  189  flowers  examined: 

Number  of  stamens 7    9   10  11  12  13   14    15    16    17    18    19    20   21 

Number  of  flowers 1     2     1     1     2    4     13    29    34    28    31     13    29     1 

Filaments  slender,  3  to  6  mm.  long,  anthers  plump,  light  yellow.  Styles 
slender,  2  to  5.  The  same  flowers  examined  as  to  stamens  have  styles 
as  follows:  1  has  2  styles,  34  have  3  styles  each,  136  have  4  styles  each, 
and  18  have  5  styles  each.  Connate  %  the  length,  hairy  in  a  belt 
about  and  just  above  the  point  of  separation,  glabrous  immediately 
about  the  base;  stigmas  oval  oblique  extending  down  the  enlarged  tips 
of  the  styles. 


1936] 


APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS 


595 


Fruit. — Very  small,  round;  the  average  of  64  fruits  weighed  and 
measured  is  a  fruit  weighing  .25  gram  with  a  vertical  diameter  of 
6  mm.  and  a  transverse  diameter  of  7  mm. ;  regular  at  base  and  apex, 
yellow,  sometimes  with  a  slight  bronze  blush  on  one  side;  skin,  thin, 
tough;  dots  none,  cavity  none,  base  rounded  to  stem  as  in  some  pears; 
stem  slender,  22  to  25  mm.  long,  erect,  green,  glabrous;  calyx  lobes  reg- 
ularly deciduous;  basin  a  slightly  depressed,  circular,  russet  scar  3  mm. 
in  diameter  which  has  a  slight 
indentation  at  the  center  repre- 
senting the  calyx  tube.  Core 
large  in  proportion  to  size  of 
fruit,  obcordate,  median,  clos- 
ed; cells  mostly  4;  of  the  64 
fruits  recorded  one  had  3  cells, 
all  of  the  others  had  4  each; 
carpels  obovate,  entire,  deeply 
concave.  Seeds  small,  plump, 
light  colored.  The  64  fruits 
produced  144  seeds,  an  average 
of  2.25  to  each  fruit.  Flesh 
yellowish,  firm,  rather  dry, 
acid  and  astringent,  Fig.  112 
is  a  fruiting  branch  of  No. 
19664  from  photograph  made 
September  16,  1916.  A  single 
fruit  may  also  be  seen  at  the 
extreme  right  in  Fig.  44,  page 
498. 

M.  toringo  is  an  interesting 
species.  Its  foliage  differs  in 
appearance  from  that  of  any 
other  form  in  the  collection; 
leaves  vary  remarkably  in 
form;  the  lobing,  the  position, 
and  color  are  distinctive  and 
they  exhibit  a  late  autumn 

change  to  shades  of  purple  that  is  seen  in  few  other  species.  The  fruit 
is  more  diminutive  than  any  other  and  is  readily  distinguished  by  the 
truncate  apex  and  the  large  size  of  the  russet  scar.  The  two  tall,  erect 
forms,  851  and  853,  have  little  to  separate  them  except  that  one  has 
yellow  and  the  other  red  fruit;  there  are  some  slight  differences  in 
bark  color  and  in  character  of  spurs, but  these  may  be  individual  rather 
than  varietal  characteristics;  in  foliage  and  manner  of  growth  the 
two  are  identical  and,  for  breeding  purposes,  fruit  color  is  the  only 
tangible  difference.  The  dwarf  spreading  form  is  distinctly  different 


FIG.  113. — FRUIT  OF  Mains  HYSLOP  CRAB 

(824),  JULY  23 

The  ground  color  of  this  fruit  is  clear 
yellow,  entirely  overspread  with  dark 
red  and  covered  with  blue  bloom.  It  is 
one  of  the  handsomest  crabs,  and  has 
been  cultivated  in  gardens  for  many 
years.  Its  history  is  unknown. 


596  BULLETIN  No.  275  [June, 

from  the  arborescent  forms,  not  only  in  habit  of  growth,  but  in  size, 
position,  and  general  aspect  of  leaves.  The  fruits  of  both  forms 
are  inclined  to  persist;  when  subjected  to  killing  frosts  they  become 
brown,  then  gradually  shrivel  and  remain  on  the  trees  until  spring. 
The  species  is  native  in  Japan,  and  was  introduced  into  Europe  and 
named  by  Dr.  von  Siebold  in  1856. 

48.  Mains  Hyslop  Crab  (824) 

One  tree  grown  from  root-grafts  made  with  scions  from  the  Arnold 
Arboretum  in  January,  1908,  is  vigorous,  erect,  and  because  of  spread- 
ing lower  branches  distinctly  pyramidal  in  form  and  perfectly  sym- 
metrical; height  20  feet  6  inches,  spread  21  feet  7  inches,  trunk  diam- 
eter 8.8  inches.  The  bark  of  trunk  is  dark  greenish-brown,  branches 
somewhat  lighter;  twigs  pubescent,  reddish-brown. 

Leaves. — Three  to  4  inches  long,  1%  to  2  inches  wide,  ovate, 
oblong,  or  elliptical;  acute  or  acuminate,  irregularly  coarsely  serrate; 
pubescent  below  when  young,  becoming  nearly  glabrous;  above,  dark 
green,  glabrous,  petioles  stout,  slightly  pubescent,  %  to  1%  inches 
long. 

Flowers. — Flowering  from  terminal  and  lateral  buds  of  shoots 
and  spurs,  4  to  7  buds  in  each  cluster.  Pedicels  1  inch  in  length,  pubes- 
cent, moderately  stout;  calyx  lobes  long-acuminate,  8  mm.  long,  pubes- 
cent both  sides.  Petals  in  bud  light  pink,  becoming  white  in  open 
flowers;  rounded  ovate  with  very  short  claw.  Flowers  expand  32  mm.; 
stamens  about  20,  filaments  slender,  6  to  8  mm.  long,  anthers  plump, 
lemon  yellow;  styles  5,  longer  than  the  filaments,  hairy  at  base, 
stigmas  oval,  oblique. 

Fruit. — Round  or  somewhat  oblong,  or  sometimes  slightly  oblate. 
Weight  as  averaged  from  100  fruits  42.44  grams;  longitudinal  diameter 
38  mm.,  transverse  diameter  44  mm.  The  ground  color  is  clear  yellow 
entirely  overspread  with  dark  red  and  covered  with  blue  bloom.  The 
skin  is  smooth,  tough,  and  rather  thick;  dots  many,  small,  round,  pale, 
conspicuous;  cavity  moderately  deep,  acuminate,  regular;  stem  me- 
dium to  long,  18  to  30  mm.,  slender,  erect,  glabrous;  basin  shallow, 
broad,  irregular;  calyx  rather  large,  closed;  lobes  long,  slender,  acu- 
minate, reflexed.  Calyx  tube  conical,  stamens  marginal.  Core  of  me- 
dium size,  cordate,  elliptical,  median,  closed;  carpels  regularly  5, 
obovate,  glabrous,  slightly  concave;  seeds  small,  dark,  averaging  6.75 
to  each  fruit.  Flesh  yellowish,  firm,  acid,  becoming  subacid,  dry,  and 
mealy  when  over-ripe.  This  is  one  of  the  handsomest  crabs,  its  history 
is  unknown,  but  it  has  been  cultivated  in  gardens  "for  many  years. 
Fig.  113  is  from  photograph  of  a  single  fruit,  natural  size,  as  it  hung 
on  the  branch;  another  fruit,  also  natural  size,  may  be  seen  between 
and  in  contrast  with  fruits  of  M.  soulardi  and  M.  sylvestris  ft,,  pi.  in 
Fig.  98,  page  571. 


1926}  APPLE  BREEDING  AT  THE  UNIVERSITY  OF  ILLINOIS  597 

49.  Mains  Yellow  Siberian  Crab  (857) 

Scions  received  from  the  Arnold  Arboretum  January,  1908.  The 
variety  is  in  the  collection  as  No.  857  and  is  at  the  present  time 
represented  as  follows:  one  tree  from  root-graft  of  January  20,  1908, 
now  sixteen  years  old,  16  feet  high,  with  spread  of  16  feet  9  inches 
and  trunk  diameter  of  5.3  inches;  has  flowered  each  year  since  1912; 
one  tree  root-grafted  January  12,  1914;  one  tree  top-worked  March  17, 
1911,  on  Virginia  Crab;  one  tree  top-worked  on  Wolf  River;  and  one 
tree  top-grafted  on  potted  paradise  stock  for  forcing  purposes;  this 
dwarf  was  grafted  February  23,  1910,  and  has  flowered  in  the 
greenhouse  each  year  since  1913.  Trees  of  this  variety  are  all  of  erect 
habit,  but  become  more  and  more  wide-spreading  as  they  get  older. 
The  variety  is  very  susceptible  to  attacks  of  the  blight  disease  and 
some  of  the  trees  have  been  severely  pruned  in  removing  diseased 
branches.  Bark  smooth,  grayish-brown  with  a  yellowish  tinge;  twigs 
light  reddish-brown. 

Leaves. — Oval,  ovate  or  oblong,  2  to  3%  inches  long,  some  smaller 
leaves  nearly  orbicular,  rounded  at  base,  shortly  acute  at  apex,  cren- 
ate-dentate,  pubescent  when  young,  becoming  glabrous  thruout  in  age; 
petioles  %  to  1%  inches  long,  slender,  pubescent. 

Flowers. — Produced  from  terminal  and  lateral  buds  of  terminal 
shoots  and  from  terminal  buds  of  short  spurs.  Number  of  buds  to  the 
cluster  for  108  clusters  examined  is  as  follows;  with  3  buds,  1;  with  4 
buds,  14;  with  5  buds,  35;  with  7  buds,  13;  with  8  buds,  2;  and  with  11 
buds,  5.  Buds  globular,  becoming  oblong,  obtusely  rounded,  greenish- 
white;  open  flowers  pure  white,  expanding  32  mm.  Pedicels  15  to  20  mm. 
long,  stout,  pubescent;  calyx  lobes  5,  linear,  acuminate,  pubescent  both 
sides;  petals  ovate,  emarginate,  claw  short,  length  15  mm.,  breadth 
11  mm.  Stamens  vary  from  10  to  20,  filaments  slender,  4  to  8  mm. 
long;  anthers  plump,  light  yellow.  Styles  5,  slender,  8  mm.  long,  dis- 
tinct nearly  to  the  base,  glabrous;  stigmas  small,  oval,  oblique.  Ovary 
densely  white  tomentose. 

Fruit. — Round  or  sometimes  slightly  oblate,  more  or  less  irregular 
both  at  base  and  apex,  cross-section  obscurely  ribbed  and  sides  com- 
monly slightly  unequal;  weight,  averaged  from  288  fruits,  is  17.6 
grams,  longitudinal  diameter  28  mm.,  transverse  diameter  33  mm. 
Yellow  with  occasionally  a  faint  pink  blush  on  one  side;  a  waxy  white 
bloom  is  evident  but  not  abundant;  skin  smooth,  thin,  tender;  dots 
few,  small,  round,  gray,  inconspicuous.  Cavity  of  medium  depth, 
broad,  obtuse,  regular;  stem  rather  long,  commonly  30  mm.,  slender, 
clavate,  erect,  green,  pubescent;  calyx  of  medium  size,  pubescent, 
closed.  Basin  shallow,  broad,  obtuse,  more  or  less  ribbed;  calyx  lobes 
long,  slender,  reflexed;  usually  persistent,  but  sometimes  deciduous  in 
the  same  manner  as  in  forms  of  M.  baccata.  Of  228  fruits  exam- 


598  BULLETIN  No.  275 

ined,  264  or  91.66  percent  retained  the  calyx  lobes  while  24  or  8.34 
percent  had  deciduous  lobes.  Calyx  tube  rather  short,  small,  conical; 
core  of  medium  size,  cordate,  median,  closed;  stamens  median,  core 
lines  clasping;  carpels  obovate,  entire,  moderately  concave.  Seeds 
plump,  of  medium  size,  dark  brown.  Seed  production  as  averaged  for 
288  fruits  is  6.98.  This  is  a  high  average;  of  25  species  and  varieties 
of  the  crab-like  forms  only  one  has  a  higher  average.  Flesh  yellowish, 
firm,  crisp,  rather  dry,  acid.  At  the  left  of  Fig.  45,  page  503,  is  a  single 
fruit  of  this  crab,  photographed  in  company  with  a  fruit  of  M.  sylves- 
tris  fastigiata  bifera  (center)  and  one  of  M.  ioensis  (right)  for  ready 
comparison  of  general  appearance,  all  natural  size. 


INDEX  TO  MALUS  FORMS  USED  IN  BREEDING 

1.  Mains  angustifolia  Michx.  (19676,  801,  1204) 447 

2.  Mains  arnoldiana  (802) 449 

3.  Mains  astracanica  (19670,  803) 453 

4.  Mains  atrosanguinea  (804) 455 

Mains  baccata  L.  Mant.  75  (1771) 458 

5.  Mains  baccata  (806),  red  fruit  443-1 459 

6.  Mains  baccata  (807),  bright  red  fruit,  late 462 

7.  Mains  baccata  var.  (808) 467 

8.  Mains  baccata  maxima  (810) 463 

9.  Mains  baccata  oblonga  (811) 470 

10.  Mains  baccata  sanguinea  (813) 473 

11.  Mains  baccata  sieboldi  (814) 476 

12.  Mains  cashmerica 478 

13.  Mains  crataegifolia  (817) 480 

14.  Mains  coronaria  (L)   Mill 480 

15.  Mains  dioica   (819) 486 

16.  Mains  floribunda  Siebold  (821) 492 

17.  Mains  fusca  (841) 495 

18.  Mains  dawsoniana  Rehder 498 

19.  Mains  halliana  (823) 499 

20.  Mains  ioensis  (825) 501 

21.  Mains  ioensis  fl.  pi.  (826) 504 

22.  Malus,    Fluke     Apple,     Mercer    County     Crab,    Fluke     Wild 

Crab    (822) 505 

23.  Malus  mains  441/1  (829) 508 

24.  Malus  mains  var.  (830) 510 

25.  Malus  mains  var.  (19667) 512 

26.  Malus  mains  var.  pendula  (832,  19688) 518 

27.  Malus  microcarpa  ( 19644) 520 

28.  Malus  niedwietzkyana  Dieck 526 

29.  Malus  prunifolia  macrocarpa  (837) 531 

30.  Malus  prunifolia  var.  (838) 533 

31.  Malus  prunifolia  xanthocarpa  (839) 537 

32.  Malus  prunifolia  var.  (856) 539 

33.  Malus  prunifolia  var.  (19651) 541 

34.  Malus  ringo  (840,  19662) 545 

35.  Malus  ringo  sublobata  (854,  19389) 549 

36.  Malus  sargenti  Rehder 555 

37.  Malus  scheideckeri  (19646) 560 

599 


600  BULLETIN  No.  275 

38.  Mains  siberica  frutico  coccinea  (19643) 564 

39.  Mains  soulardi  (Bailey)  Britton  (846,  19665) 567 

40.  Mains  spectabilis 572 

Mains  spectabilis  var.  1615  (848) . . . ' 572 

41.  Mains  spectabilis  var.  458/4  (849) 575 

42.  Mains  sylvestris  fastigiata  bifera  (820) 579 

43.  Mains  sylvestris  fl.  pi.  (833) 583 

44.  Mains  sylvestris  (19631) 585 

45.  Mains  toringo  Carriere «...  586 

Mains  toringo,  red  fruit  (851) 586 

46.  Mains  toringo,  yellow  fruit  (853) 588 

47.  Mains  toringo  dwarf,  spreading  (852,  19664) 592 

48.  Mains  Hyslop  Crab  (824) 596 

49.  Mains  Yellow  Siberian  Crab  (857) . .  .597 


THE  LIBRARY  OF  TH£ 
OCT  2  1  1931 

UNIVERSITY  OF  ILLINOIS. 


UNIVERSITY  OF  ILLINOIS-URBANA 


